ACPAT Journal 2022

Four Front Number 9 | March 2022

The Magazine of the Professionals in Animal Therapy

Association of Chartered Physiotherapists in Animal Therapy www.acpat.org

www.acpat.org

Your animal deserves the best.

Choose a professional.

Choose a Chartered Physiotherapist.

The Association of Chartered Physiotherapists in

Animal Therapy

The professionals in animal physiotherapy and rehabilitation ACPAT is a specialist interest group of the Chartered Society of Physiotherapy, the professional membership organisation for all physiotherapists in the UK. All ACPAT category A physiotherapists receive training to the highest standard and have the MCSP qualification (Member of the Chartered Society of Physiotherapy), meaning that they first qualify in human physiotherapy before starting a career in animal care. They have accompanied and treated British Team horses at European, World and Olympic games since 1992 and are the only allied Heath profession to have supported the veterinary team at London 2012 Olympic games. To find your local Chartered Physiotherapist contact www.acpat.org.uk

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CONTENTS

4.

Tribute to Claudine Chart

5.

Show Jumping Biomechanics: What Do We Know And How Can It Be Useful In A Physiotherapy Setting?

Kristin Dean, B.App.Sc(Phty), CERP, APA L2 Animal Physio (Equine)

6.

The Importance Of Prehabilitation In Sports Performance Tracy Carter, DVM BSc MRCVS / Prehabvet

8.

Thinking Outside The Box: Could Alternative Grazing Systems Be The Future In Improving Equine Physical And Mental Health?

Cynthia Joanne Naydani, BSc (Hons), MSc

11. Case Study: 9 Year Old Female Neutered Staffordshire Bull Terrier Ciara Glaisher ACPAT RAMP CSP HCPC

13. A Systematic Approach to Comparing Thermal Activity of the Thoracic Region and Saddle Pressure Distribution beneath the Saddle in a Group of Non-Lame Sports Horses Russell MacKechnie-Guire Mark Fisher Helen Mathie Kat Kuczynska Vanessa Fairfax Diana Fisher and Thilo Pfau

25. Horses Inside Out Conference - 2nd and 23rd February 2020 Summary and Take Home Messages

29. Pain Management And The Importance Of The Multidisciplinary Team In Rehabilitation For Our Veterinary Patients Dr. Katie Smithers, BVSc certavp(va) pgcertvps MRCVS Veterinary Surgeon

33. The Hoof Horse Connection Yogi Sharp DipWCF BSc (Hons)

38. Centaur Biomechanics International Equine Sports Science Virtual Summit - 3rd October 2020 Sue Palmer, MCSP, IHRA, ACPAT and RAMP Chartered Physiotherapist, BHSAI

40. Equine Gastric Ulcer Syndrome James Wallace BVMS GP CertEP CertEM (Int Med) MRCVS CertEP RCVS Advanced Practitioner Internal Medicine Equine Veterinary Surgeon

42. Research Digest

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In Loving Memory

Claudine Chart

O

especially kind, approachable and always happy to support others.

Her wider scope of practice in human physiotherapy was also impressive, where not only did this include postgraduate musculoskeletal practice, but Claudine also spoke with a strong sense of empathy and interest during her time working in neurological rehabilitation.

She adored being a mother and worked hard as a single Mum to provide for Emilia.

ur dear friend Claudine Chart, ACPAT Veterinary Physiotherapist who qualified in 2018 at Hartpury University.

Claudine sadly passed away unexpectedly in August 2020, leaving her 2 year old daughter Emilia. She was undergoing treatment for non-advanced bowel cancer and had a severe reaction to the treatment.

Claudine loved working with animals as a veterinary physiotherapist, as well as looking after her own collection of ponies, chickens, a dog and a cat. She is remembered by those she trained with during her Veterinary Physiotherapy studies as being

Claudine was always smiling, had a cheeky sense of humour and great compassion, as well as courage and determination. She is greatly missed.

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Show Jumping Biomechanics: What Do We Know And How Can It Be Useful In A Physiotherapy Setting?

Kristin Dean, B.App.Sc(Phty), CERP, APA L2 Animal Physio (Equine) Biomechanical analysis is widely used in human athletes to evaluate and optimise performance. While it is used frequently in research to study equine movement and performance, there is also a place for its use in the clinical setting, where it can have significant benefits in aiding in the diagnosis of injury, the creation of management plans, monitoring rehabilitation progress and improving performance. This is especially true in show jumping, where the movements are complex and quick.

At present, the main tools available to bridge the gap between physiotherapy and biomechanics are high-speed video

with kinematic analysis, inertial motion units (IMUs) and force plates or shoes.

These tools can provide objective measurements of joint function, limb symmetry and spinal mechanics. This can provide a baseline of a horse’s “normal” movement pattern and thus allow us to identify abnormal movements, which may improve our ability to catch pathology or injury earlier.

There is presently significant research that has identified key performance indicators for a successful show jump.

We know that take-off is the key phase in show jumping, and that successful horses will have a higher vertical velocity

of centre of mass (COM), increased height of the COM and decreased hind limb placement in relation to the COM. We can use these biomechanical indicators to achieve more effective results in our clinical practice - identifying the main areas to ideally focus on such as improving the efficiency of the stretch shorten cycle (SSC), ensuring muscular power and strength of the hindquarters (in particular the gluteus medius), and advising riders on training parameters, especially in relation to symmetry and anaerobic fitness.

Equine Grass Sickness CPD

£120

This CPD course explores all aspects of the often-fatal disease, Equine Grass Sickness (EGS).

PER ATTENDEE

The University of Edinburgh and Equine Grass Sickness Fund have launched a continuing professional development (CPD) online course.

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This course is for anyone with an interest in EGS. Equine Physiotherapists are being approached to help with rehabilitation of the chronic horses' recovery.

CPD HOURS

Further information:

edin.ac/vet-egs-cpd

10%

OF FEE GOES TO EGSF

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The Importance Of Prehabilitation In Sports Performance Tracy Carter DVM BSc MRCVS / Prehabvet In any training centre, program, class, or lesson - there’s an emphasis on foundation. Mirroring the adage, “perfect practice makes perfect”, sports enthusiasts plan puppies or partners years in advance.

New information is debated and dissected, aimed at consistent sports progression.

Canine partnerships focus on developing in-depth training comprehension, resulting in faster dogs and narrowed competition. Skill increases are followed by calls for safety.

A typical year provides options for significant travel with multiple national or international events.

Performance strategy becomes harder to manage, as year-round opportunities for partnership increase across all levels. More opportunity demands more practice, increasing repetition and physical preparation. A fine line stretches between maintaining peak performance, or maintenance problems.

between competitor knowledge and application. Starting with education, young dog assessments evaluating gait, posture, and muscle function are ideal to demonstrate fatigue markers.

Prescriptive exercise plans allow competitors to incorporate improvements into performance building blocks. Variability in training plans becomes more suited for a sportsspecific purpose.

Clinicians can then collaborate with coaches to develop appropriate movement targets and place them into increasing skill challenges. Dynamic plans focused on mental and physical control help accelerate learning and confidence.

Apply by reviewing footage of training sessions, providing individualized feedback that capitalizes on previous foundation.

That emphasis on protection and partnership creates enhanced performance measures, with recent attention to regulatory standards in agility. Changes in the past five years include altered jump heights, a minimum obstacle distance, and modified equipment design.

Competitors routinely put their partners first, looking for proactive measures in the arena and preventative care outside of it.

Balancing the later sustainable athlete requires a clinical plan with teamwork across disciplines. prioritizing Agility was merely a Advising clients to train a neutral stance is an excellent place to Consultations principles will demonstration at Crufts start in prehabilitation: this will help highlight areas of asymmetry scientific help progress partnerships in 1971; initial training was and provides groundwork for self-assessment. and improve strategies based with the dog on a for goal-based outcomes. handler’s left, an extension At this stage, prehabilitation helps of a competitive obedience skill. Dogs Prehabilitation is essential for these form schedules for periodization and commonly kept to a neutral pace. It was teams‡. Although training protocols specificity. recognized as an official Kennel Club initially emphasize proprioception, this sport in 1980. can taper with precedence to skills and If rehabilitation is needed, absent is limited in scope. Clinicians know that sports-specific training principles can ACPAT was launched in 1985. sports management is not a steadyslow progress.

Veterinary medicine followed suit much state, where perfect practice meets later. In 2018, the linear improvement.

Remedial training of the athlete may American College of Veterinary Sports Medicine (ACVMR) achieved status as a fully recognised speciality.

Foundation now includes an emphasis on developing body awareness, though learning patterns and social habits remain an early focus. Minimum age requirement for most competitions is 18 months old, with exception of sheepdog trials†. Athletes usually approach a competitive peak from three to seven years old, dependent on qualifying processes.

Dogs will be trained throughout their career for event strategy and skill work.

Demands for improved athletic welfare exists, but with fractured awareness of existing clinical resources. Protocols for safety standards or skill progression are easy to find, but current available and free information on conditioning often disregards individualization.

Client expectations can mirror sports principles for skill outcomes, expecting steady-stage advances.

If competitor consciousness then drives a need for prehabilitation, what does this look like in practice?

Placing prehabilitation into a basic sports foundation helps narrow the gap

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be needed before discharge, as well as focusing on observational development of the handler. Both are skills that could be incorporated into a prehabilitation plan.

Our goal is not to create perfect practice, but enable teams a continued pursuit of sport.

Standards that improve owner education and athletic care also provide professional learning opportunities for research, interdisciplinary knowledge, and future patient outcomes.

†

Event

Age

Performance Requirements by Sport

Progression

Agility

15-18 months

Winning Points

Flyball

12-18 months

Can earn title points based on speed

Obedience

6 months

Herding

Canicross

KC: 1-7

Runs/Day

Season

Default Position

1-4

April-Oct

Variable

Divisions (determined by time)

Heats (3-5 runs)

Summer

Sprint

Winning

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1-2 classes

All Year

Heel

Any

None

-

Multiple

All Year

Partial Crouch

12-18 months

-

Age / Distance

Sept-May

Pull

‡

Event

Levels

UKA: 4

Scenarios for Prehabilitation by Sport

Presentation

Agility

Reduced muscle control Reduced fitness for sport Lack of postural variation (during skill acquisition or reward focus) Biopyschosocial contributions

Flyball

Suboptimal shock absorption Reduced fitness for sport

Obedience

Crabbing Shortening of cervical strap musculature Cardiovascular endurance

Herding

Lordosis Decreased sternal glide (movement in partial elbow and shoulder flexion) Decreased functional shoulder extension Chronic changes to fascial elasticity

Canicross

Reduced flexibility (pulling) Decreased functional hip extension Gluteal tension

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Thinking Outside The Box: Could Alternative Grazing Systems Be The Future In Improving Equine Physical And Mental Health?

Cynthia Joanne Naydani BSc (Hons), MSc Introduction When imagining an “idyllic” equine environment many people likely think of lush green pastures and warm, comfortable stables. But, what if horses were able to offer their own perceptions? A growing body of scientific evidence indicates that typical domestic horse management, which generally caters as much to human convenience as to equine needs, is not necessarily conducive to healthy, happy horses. In fact, much of the available research suggests that conventional management of domestic horses can have serious ramifications on both physical and psychological well-being.

It is the increasing acknowledgement of the disparities between natural ethological needs and conventional management that has, at least in part, spurred the growing popularity of alternative grazing systems. These systems prioritise the facilitation of the 3Fs: Freedom, Friends, and Forage, which are the pillars upon which equine welfare is supported. Yet, much is still unknown about these systems and their applications as potential solutions to some of the most prevalent welfare issues affecting domestic horses in the UK, and worldwide.

This review aims to discuss alternative grazing systems, including an exploration of why new management approaches are necessary, how these systems may be beneficial, and what research is needed prior to reaching a clear conclusion regarding their usefulness.

“Alternative” to what?

The first step to understanding alternative grazing systems is to identify what they are alternatives to.

Conventional management of domestic horses in the UK and abroad centres around individual stabling and limited access to turnout, typically in simplistic grass fields

(Hockenhull and Creighton, 2014).

Forage provision is often intermittent and supplemented with high-energy concentrates (Hockenhull and Creighton, 2014). These common housing and feeding strategies can promote obesity, which is among the most pressing equine welfare issues in the UK (Rioja-Lang et al., 2020).

If unmanaged, obesity may lead to comorbidities including laminitis and Equine Metabolic Syndrome (EMS) (Geor, 2010). Recommended strategies to treat and/or prevent these conditions frequently focus on nutritional management, with an emphasis on restricting pasture access (e.g., Gill et al., 2017), increasing social isolation and limiting movement. Collectively, these conventional approaches to husbandry fail to consider the natural needs of horses, who evolved to live socially, traveling across varied terrain while grazing near-continually on diverse forages (McGreevy, 2012).

The consequences of the conflicts between domestic horse management and their species normal behaviours are well-documented. Restricted forage intake and limited movement are risk factors for gastrointestinal issues including colic and Equine Gastric Ulcer Syndrome (EGUS) (Aranzalez and Alves, 2013; Mills and Clark, 2007). Stress and frustration stemming from isolation, unsatisfied motivation to move, and lack of access to forage can provoke stereotypic behaviours, aggression, displays of conflict behaviours, and learned helplessness (Ruet et al., 2019). Therefore, alternative grazing systems propose an unconventional, but comparatively natural, approach to equine management.

Types of alternative grazing systems Various alternative grazing systems are currently being utilised in the UK, including track and

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Equicentral systems, rewilded areas, and woodland/moorland habitats (Furtado, King, and Pinchbeck, 2021). For this review, the two most popular options, track and Equicentral systems, will be discussed.

Track (aka “Paddock Paradise”) systems were initially introduced by Jamie Jackson, an American natural hoof care practitioner (2007). He was inspired by observations of wild mustangs, who Jackson argued had superior health and soundness when compared with domestic horses living in conventional management systems. Tracks are low-/ no-grass systems whereby horses, living socially, have access to what can be as simple as the perimeter of a field, or a more complex network of passageways.

Resources, including hay, water, and shelter, are distributed throughout the area, encouraging movement and exploration.

Established tracks are often surfaced with variable terrain (e.g., pea gravel, concrete pavings) and include enrichment items such as sandpits, logs, hedgerows, and natural water bodies.

Central field areas are usually either cut for hay, or strip-grazed over winter when the grass is mature, and lower in laminitis-provoking sugars (Longland and Byrd, 2006).

Equicentral systems were developed

by Jane and Stuart Myers (www. equiculture.net ). Their ethos is rooted in consideration for both environmentaland horse-health. Equicentral systems consist of several grass paddocks connected to a central “loafing area”: a hardstanding yard with shelter, forage stations, waterers, and perhaps other features such as arenas. Horses have free access to the loafing area while paddocks are grazed rotationally.

This approach aims to encourage biodiversity, improve soil health,

minimise mud, and avoid the consumption of stressed, sugary grasses. Horses travel between paddocks and the loafing area, and have free access to communal shelters rather than receiving individual stabling.

Suggested benefits of alternative grazing systems Supporters of alternative grazing systems report benefits to equine physical and psychological wellbeing. Many people become motivated to explore alternative management options after their horses experience health problems such as laminitis or EMS, and over 60% of owners report their horse(s) lost weight after transitioning to track systems (Furtado, King, and Pinchbeck, 2021). Track systems are suggested to help maintain healthy body condition due to increased movement and decreased grass consumption in favour of lower-nutrient hay.

Movement in alternative grazing systems is presumably low-intensity exercise supported by aerobic metabolism that partially relies on stored energy (i.e., fat) for fuel. Aerobic conditioning increases oxidative capacity, delaying onset of fatigue which subsequently decreases injury risk (Rivero and Piercy, 2008).

Data indicate that horses with access to movement via turnout have improved fitness and bone strength than horses either exclusively stabled or stabled with light-moderate ridden exercise (GrahamThiers and Bowen, 2013). Additionally, research indicates that movement over variable surfaces and slopes, a design element of many track systems, can enhance proprioceptive abilities and lead to advantageous physiological adaptations (Dyson, 2017; FEI, 2014). Trotting over poles has been demonstrated to increase joint flexion and range of motion, potentially improving visuomotor coordination, proprioception, endurance, muscular strength, and rehabilitation post-injury/lameness (Brown et al., 2015).

As such, the inclusion of obstacles, such as logs, in alternative systems may lead to similar improvements in physical function.

Competition horses are often kept in isolated, restrictive stables over concerns that turnout will lead to injury and/or delayed post-exercise recovery that could penalise future performance.

However, data indicate that the provision of adequate space, such as what is theoretically offered by alternative

management systems, minimises injury risk (Suagee-Bedore et al., 2021), and that agonistic interactions are avoided through the provision of resources such as ad lib forage (Benhajali et al., 2009.

Furthermore, Connysson, Rhodin and Jansson (2019) reported that group turnout sped post-exercise recovery and restored energy balances in Standardbred trotters more effectively than stabling. Overall, enhanced quality and quantity of movement, potentially facilitated by alternative grazing systems, may lead to substantial physical benefits for domestic horses.

An inherent component of alternative grazing systems is the provision of socialisation, foraging, and exploratory opportunities. These are crucial for adequate welfare, and the ramifications associated with their prevention are welldocumented.

Stereotypic behaviours are widely recognised indicators of suboptimal welfare, stemming from an animal’s attempts to cope with aversive environments (Broom, 2019). It is suggested that stereotypies arise due to stress and frustration caused by inability to access desired resources (Henderson, 2007).

Stereotypies, including crib-biting and weaving, have been linked to restricted access to forage, and isolation (McGreevy et al., 1995; Whisher et al., 2011; Yarnell et al., 2015). In comparison, evidence indicates psychological benefits associated with opportunities to display species-normal behaviours. For example, Löckener et al. (2016) reported a positive cognitive bias when isolated horses were given the opportunity to socialise. Ruet et al., (2019) agree that socialisation opportunities are integral to maintaining an acceptable quality of life, and that optimal welfare cannot be obtained if horses are individually housed. Therefore, alternative grazing systems that ensure horses can socialise, roam, and forage are likely to have a positive impact on welfare.

Based on the aforementioned evidence, one could reasonably assert that alternative grazing systems are not necessary, so long as a horse is given adequate group turnout.

However, these systems are unique in that they provide something most conventional systems do not: choice. In conventional systems, humans make nearly all decisions for their horses.

Comparatively, in alternative systems horses exert individual agency to decide (with their herd) when to take shelter, where to go, and whom to socialise with.

As the emphasis in animal welfare science shifts from giving animals “a life worth living” to “a good life”, an increasing

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amount of importance is placed on this ability to control aspects of one’s own life (FAWC, 2009; Mellor et al., 2020).

By giving horses the power to explore opportunities, seek out pleasurable experiences, and gain confidence, alternative grazing systems may prove to support positive welfare states, rather than simply preventing poor welfare.

Can’t we just ride more?

It is reasonable to wonder if increasing ridden or other human-led exercise (HLE) is suitable compensation for deficits associated with conventional management.

However, evidence suggests that HLE cannot compensate for inadequate opportunities to perform normal behaviours. Ruet et al. (2019) found that time spent being ridden did not alleviate stress caused by isolation and subsequent displays of stereotypies, aggression towards humans, or learned helplessness. A preference test by Lee et al., (2011) showed that horses preferred to stay in an individual stable than exercise on a treadmill, but chose turnout over stabling, particularly when out with another horse. Additionally, the physiological benefits of HLE may differ in theory versus practice. Giles et al. (2014) found that horses ridden at low intensities did not have reduced risk of obesity than their unridden conspecifics.

While increasing ridden exercise may appear to be a simple solution, it is unlikely to be a feasible option for many owners. A recent survey of 804 horse owners in the UK found that only 10.3% of respondents felt able to exercise their horses as much as they wanted, without any substantial barriers (Naydani, 2021).

The main limitations on HLE were identified as weather, time, and access to suitable riding facilities. Overall, existing data indicate that it is necessary to give horses opportunities to exercise, explore, and socialise without relying on humanled exercise to meet their needs.

Future research Though the support for alternative grazing systems appears convincing, it is important to acknowledge that, at this stage, it is currently anecdotal, theoretical, or extrapolatory.

Alternative grazing systems, and the horses who live in them, have yet to be the subjects of direct scientific study.

It is necessary to collect measurable, scientifically validated data from these systems to determine if, and how, alternative grazing systems contribute positively to welfare.

Conclusion To summarise, the existing research on equine management indicates that conventional husbandry frequently fails to provide outlets for species-normal behaviours including socialisation, roaming, and foraging. This is detrimental to welfare, with documented effects on physical health (e.g., obesity, laminitis, EGUS) and psychological wellbeing (e.g., stereotypies, unwanted behaviours). By providing freedom, friends, and forage, alternative grazing systems are proposed to be a potential solution for the existing conflict between modern management and natural needs. However, dedicated research has yet to explore their usage, and is a vital next step in improving the welfare of domestic horses in the UK, and abroad.

References Aranzalez, J. R. and Alves, G. E. (2013) ‘Equine gastric ulcer syndrome: Risk factors and therapeutic aspects’, Revista Colombiana de Ciencias Pecuarias, 27(52), pp. 157–169.

Benhajali, H. et al. (2009) ‘Foraging opportunity: a crucial criterion for horse welfare?’, Animal, 3(9), pp. 1308–1312.

Broom, D. M. (2019) ‘Abnormal behavior and the self-regulation of motivational state’, Journal of Veterinary Behavior, 29, pp. 1–3.

Brown, S. et al. (2015) ‘Swing phase kinematics of horses trotting over poles’, Equine Veterinary Journal, 47(1), pp. 107– 112.

Connysson, M., Rhodin, M. and Jansson, A. (2019) ‘Effects of horse housing system on energy balance during post-exercise recovery’, Animals, 9(11), pp. 1–9.

Dyson, S. (2017) ‘Equine performance and equitation science: Clinical issues’, Applied Animal Behaviour Science, 190, pp. 5–17.

Farm Animal Welfare Council (2009) Farm animal welfare in Great Britain: Past, present and future. London.

FEI (2014) Equestrian Surfaces - A Guide.

Furtado, T., King, M. and Pinchbeck, G. (2021) The use of alternative grazing systems in the UK. Liverpool.

Geor, R. J. (2010) ‘Nutrition and exercise in the management of horses and ponies at high risk for laminitis’, Journal

of Equine Veterinary Science, 30(9), pp.

463–470.

in the Thoroughbred horse’, Equine Veterinary Journal, 27(2), pp. 86–91.

Giles, S. L. et al. (2014) ‘Obesity prevalence and associated risk factors in outdoor living domestic horses and ponies’, PeerJ, (1), pp. 1–17.

Mellor, D. J. et al. (2020) ‘The 2020 five domains model: Including human–animal interactions in assessments of animal welfare’, Animals, 10(10), pp. 1–24.

Gill, J. C., Pratt-Phillips, S. E. and Siciliano, P. D. (2017) ‘The effect of time- and space-restricted grazing on body weight, body condition score, resting insulin concentration, and activity in grazing horses’, Journal of Equine Veterinary Science, 52(2017), pp. 87–88.

Mills, D. S. and Clarke, A. (2007) ‘Housing, Management and Welfare’, in Waran, N. (ed.) The Welfare of Horses.

Springer, pp. 77–97.

Graham-Thiers, P. M. and Bowen, L. K. (2013) ‘Improved ability to maintain fitness in horses during large pasture turnout’, Journal of Equine Veterinary Science, 33(8), pp. 581–585.

Henderson, A. J. Z. (2007) ‘Don’t fence me in: Managing psychological well-being for elite performance horses’, Journal of Applied Animal Welfare Science, 10(4), pp. 309–329.

Hockenhull, J. and Creighton, E. (2014) ‘Pre-feeding behaviour in UK leisure horses and associated feeding routine risk factors’, Animal Welfare, 23(3), pp.

297–308.

Jackson, J. (2006) Paddock paradise: A guide to natural horse boarding. Lompoc, CA: Star Ridge Publishing.

Janczarek, I. et al. (2016) ‘Can releasing racehorses to paddocks be beneficial?

Heart rate analysis - Preliminary study’, Annals of Animal Science, 16(1), pp. 87–97.

Lee, J. et al. (2011) ‘Preference and demand for exercise in stabled horses’, Applied Animal Behaviour Science, 130(3– 4), pp. 91–100.

Löckener, S. et al. (2016) ‘Pasturing in herds after housing in horseboxes induces a positive cognitive bias in horses’, Journal of Veterinary Behavior: Clinical Applications and Research, 11, pp. 50–55.

Longland, A. C. and Byrd, B. M. (2006) ‘Pasture Nonstructural Carbohydrates and Equine Laminitis’, The Journal of Nutrition, 136(7), pp. 2099S-2102S. McGreevy, P. D. (2012) Equine behavior: A guide for veterinarians and equine scientists. Second. Oxford: Saunders Elsevier.

McGreevy, P. D. et al. (1995) ‘Management factors associated with stereotypic and redirected behaviour

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Naydani, C. (2021) Movement as medicine: Horse owner perceptions of the potential for movement and exercise to improve the welfare of horses. University of Edinburgh.

Rioja-Lang, F. C. et al. (2020) ‘Determining a welfare prioritization for horses using a Delphi method’, Animals, 10(4), pp. 1–16.

Rivero, J. L. L. and Piercy, R. J. (2008) ‘Muscle physiology: Responses to exercise and training’, in Equine Exercise Physiology: The science of exercise in the athletic horse. Saunders Elsevier, pp. 4347,60-62.

Ruet, A. et al. (2019) ‘Housing horses in individual boxes is a challenge with regard to welfare’, Animals, 9(9), pp. 1–19.

Suagee-Bedore, J. K., Linden, D. R. and Bennett-Wimbush, K. (2021) ‘Effect of Pen Size on Stress Responses of Stall-Housed Horses Receiving One Hour of Daily Turnout’, Journal of Equine Veterinary Science, 98, p. 103366.

Whisher, L. et al. (2011) ‘Effects of environmental factors on cribbing activity by horses’, Applied Animal Behaviour Science, 135(1–2), pp. 63–69.

Yarnell, K. et al. (2015) ‘Domesticated horses differ in their behavioural and physiological responses to isolated and group housing’, Physiology and Behavior, 143, pp. 51–57.

Case Study: 9 Year Old Female Neutered Staffordshire Bull Terrier Ciara Glaisher ACPAT RAMP CSP HCPC O sought physio from advice on a local social media page describing her symptoms.

ROM R carpus mild hyperextension + 10degree MCL laxity.

HPC: 8 week history of urinary incontinence, generally seeming old and sad, plus noticed intermittent shakiness of hindlimbs for the last 6-8 weeks.

Occasionally hindlimbs buckle under her.

Right forelimb also intermittently points her toes outwards. Last few weeks has been slow to walk up hills. Last 3 weeks has occasionally been sleeping with eyes open, and last few days has occasionally ‘winked’ at owner, with left eye closing.

Seen vet three times since symptoms began, initially treated for UTI, then a ‘dropped bladder’. On day of initial physio appt, was also diagnosed with reduced kidney function, given new medications to start that evening.

Impression: I worked on a theory that this dog potentially had lumbosacral stenosis, affecting R>L S1/2, potentially with Lower Motor Neuron bladder deficit (from re-reading university notes, explaining neural control of bladder; S1+2 nerve roots). Complicated by reduced kidney function diagnosed, which she had new medication for, so discussion with owner to explain we don’t know how much of her symptoms could be caused by each pathology. Explained that kidney function would be highly unlikely to cause the concurrent muscle atrophy and altered gait pattern, so worth treating what we find from a musculoskeletal perspective.

Owner was very keen to do everything possible to maintain quality of life.

Observations on initial appt: BCS 2.5/5, happy demeanour around owner’s garden.

Posture was standing with increased extension of L>R stifles and tarsi. Mildmoderately flexed lumbosacral spine, with tail tucked. Sitting tended to sit on one side, always done.

Gait Ax: In walk, R carpus ‘dishing’, slight increased carpal extension on weightbearing, slightly wide forelimb stance. Intermittently wide hindlimb stance. Slightly laterally flexed lumbar spine to R. In trot, laterally flexed lumbosacral spine to right, on 3 tracks.

Running, tended to bound around. Able to do walk in tight circles and back-up 1-2 strides, but difficulty assessing due to anxiety.

Postural sets no deficit noted.

Reflexes: Knuckling immediate replacement. Paw placement good.

Cutaneous trunci absent entire spine.

Myotatic reflexes unable to assess due to fear of reflex hammer. Clonus unable to assess as not relaxed enough (never layed down during appt.s).

Palpation: Muscle atrophy R side middle gluteal, quadriceps, mildly hamstrings. L side quadriceps + mildly hamstrings.

PAIVMs in all directions on thoracic and lumbar spine all NAD; normal mobility, no pain reactions. Dorsoventral on S1-3 likely painful as she stopped moving + concentrated on physio (Subtle body language signal only).

Treatment: Applied NMES to S1/2 nerve roots x5minutes bilaterally. NMES to gluteals, required intensity of 23 to activate muscle contraction. Manual therapy PAIVMs dorsoventral glides to S1/2, grade 3; to relieve pain and stimulate neural firing. Advised strengthening exercises including sit-to-stands, controlled uphill walking, playing tug of war.

Review 2 weeks later: Owner reported urinary incontinence had resolved immediately following initial appointment.

They started new kidney medication the same evening, but highly unlikely to have had effect immediately as needed to build up levels in her system. Observations showed much improved gait pattern, no longer wide base of support. Standing posture less flexed lumbosacral spine, tail still tucked. Palpation revealed increase muscle bulk in gluteals + quadriceps.

Treated with repeat NMES to S1/2 nerve roots x10mins, NMES to gluteals + quadriceps x5mins. Progressed exercises to rhythmic stabilisations on 3 legs, plus wobble cushion standing. Planned to monitor R carpus + splint/support if any signs of lameness or increased laxity.

Case was left open for owner to contact me when urinary incontinence returned, or deterioration of functional abilities.

No contact for months, however I did see a post from the owner on the original social media page, 4 months later. When I asked how she was doing, the owner replied happily that urinary incontinence has never returned since the first physio

11

treatment, she was functioning well and happy with strengthening exercises/ advice. Sadly, a few months later I saw another post, to say she was PTS, for other unrelated reasons.

Discussion/learning point: Unfortunately the veterinarian involved is a local GP vet known to never refer cases (to any specialty), and does not see the need for Physiotherapy. He did agree to me seeing this case, so consent officially gained, although he did say the problem was not ‘anything to do with physio’ and did not understand the potential benefits. It was difficult to converse with him, regarding the potential cross-over effects of kidney medication and physio treatment, so we can only conclude our interpretation of signs/symptoms.

In my opinion, although the clinical signs of this patient could have been at least partly, or fully, due to kidney function, I would be very surprised if medication would have such an immediate effect on incontinence. Of all the signs/symptoms, the owner was most concerned about the incontinence, as it seemed to be causing a lot of stress in the dog by soaking her bed multiple times a night (O washed 3 blankets every night). From reading about neural control of the bladder, it made sense that the nerve roots involved (S1/2) are also susceptible to stenotic changes.

The localisation of muscle weakness and behavioural changes fit with lumbosacral stenosis, a common ailment in older dogs, so I treated on this theory. Having spoken to a human physio colleague specialising in Pelvic Health, it is not common practice to stimulate nerve roots for incontinence as a physio, however this is available as a surgical option when appropriate.

There may be a difference in anatomy, where canine nerve roots are closer to the surface than human, so may be more accessible.

As NMES is used for stimulating nerve following injury, as well as muscle stimulation, I felt it was an appropriate modality to try. At no point did I expect immediate improvement, and the owner expected to require multiple sessions with follow-up maintenance sessions, if it was to work at all. However, with this one experience, I will now consider NMES to nerve roots for urinary incontinence in the future, as long as correct veterinary management is also pursued, and there are signs of a LMN bladder.

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A Systematic Approach To Comparing Thermal Activity Of The Thoracic Region And Saddle Pressure Distribution Beneath The Saddle In A Group Of Non-Lame Sports Horses Russell MacKechnie-Guire1,2 Mark Fisher3, Helen Mathie4, Kat Kuczynska5, Vanessa Fairfax 6, Diana Fisher3 and Thilo Pfau2 1 Centaur Biomechanics, 25 Oaktree Close, Moreton Morrell, Warwickshire CV35 9BB, UK 2 Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookman’s Park, Hatfeld AL9 7TA, UK; TPFau@rvc.ac.uk 3 Woolcroft Saddlery, Mays Lane, Wisbech PE13 5BU, UK; woolcroft2002@yahoo.co.uk (M.F.); dianafsher007@yahoo.co.uk (D.F.) 4 Helen Mathie Physiotheraphy, Estate House, Matfen NE20 0RP, UK; helenmathiephysio@gmail. com 5 Vet-IR, 83 Ducie Street, Manchester M1 2JQ, UK; kat@vet-ir.com 6 Fairfax Saddles, The Saddlery, Fryers Road, Bloxwich, Walsall, West Midlands WS3 2XJ, UK; vanessa.fairfax@fairfaxsaddles.com * Correspondence: rguire@rvc.ac.uk

Simple Summary Thermography is a non-invasive method for measuring surface temperatures. Due to its ease of use, it may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified temperatures at specific locations (left/right) of the thoracic region at three-time points; a Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) during a period of exercise. Differences between saddle widths in the cranial/caudal mean and peak saddle pressures were found.

The maximum thermal temperatures increased post lunge and post ridden compared to the baseline. No difference between post lunge and post ridden exercise were found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

Abstract Thermography is a non-invasive method for measuring surface temperatures and may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures.

A thermal camera quantified minimum/ maximum/mean temperatures at specific locations (left/right) of the thoracic region at three-time points: (1) baseline;

(2) post lunging; (3) post ridden exercise in eight non-lame sports horses ridden by the same rider. A Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) in the cranial and caudal regions. General linear mixed models with the horse as the random factor investigated the time point (fixed factor: baseline; lunge; ridden) and saddle ft (fixed factor: correct; wide; narrow) on thermal parameters with Bonferroni post hoc comparison. The saddle pressure data (grouped: saddle width) were assessed with an ANOVA and Tukey post hoc comparison (p = 0.05). Differences between the saddle widths in the cranial/ caudal mean (p = 0.05) and peak saddle pressures (p = 0.01) were found. The maximum temperatures increased post lunge (p = 0.0001) and post ridden (p = 0.0001) compared to the baseline. No difference between post lunge and post ridden exercise (all p = 0.51) was found.

The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

1. Introduction The saddle is an essential piece of equipment coupling the horse and rider. The effects of saddle ft [1–3] and saddle design [1–11] on equine health and performance are becoming better understood. Incorrect saddle ft is thought

13

to be a potential contributing factor in the context of back problems, poor attitude to work and poor performance [3,12–17].

One way of quantifying saddle ft is the use of an electronic pressure mat positioned beneath a saddle. This has been shown to be a reliable and accurate way to quantify saddle pressure distribution [18,19] in the static and dynamic horse [1–3,9,10,15,20– 22]. Although the accuracy, repeatability and application of pressure mapping systems has been demonstrated [18,19], the costs and time associated with data collection/processing is a limiting factor for its use outside of a laboratory setting.

An association between lameness and spinal dysfunction has been reported [14,23–27]; however, the causal relationship between the two needs further investigations. Saddle ft should be considered as a contributing factor in this context. In saddles which had been fitted both statically and dynamically following industry guidelines, pressures in the region of the 10th–13th thoracic vertebrae were of a magnitude higher than those thought to cause back discomfort [15].

When the magnitude of pressure was reduced, with saddlery modifications, limb kinematics at trot [6], gallop [8] as well as jumping technique [7] were altered. This emphasizes the importance of saddle ft and the relationship between (high) saddle pressures and locomotor features.

Saddles are generally fitted to the horse and rider by a qualified saddle fitter who will assess the saddle both statically and dynamically. This assessment is subjective and relies on the skills and experience of the saddle fitter. This process, like other subjective assessments, e.g., visual lameness assessments [28–32], will likely have limitations. The subjective nature of the saddle fitting, along with the effect that saddle ft can have on the locomotor apparatus of the horse [1–3,5–7], has led to an increased availability of a variety of objective measuring systems aiming to assist with saddle fitting, potentially providing a more quantitative approach.

Thermography has been used in veterinary medicine [33], and specifically as part of a diagnostic technique when evaluating back-related conditions [34]. It has been proposed as a potential system to quantify saddle ft by evaluating thermal pattern distribution [35–37], providing a non-invasive diagnostic imaging technique which detects the superficial heat emission from the body by infrared radiation, indicative of the temperature of the body surface. It has been proposed that a thermal imaging camera can detect hyperthermic activity (due to friction/ pressure) with more than 10 times higher sensitivity than the human hand [38].

Thermography has been used to identify focal hypothermic and hyperthermic areas in the horse and saddle [7,35–38].

Thermal symmetry of the underside of the saddle [35–37] and thoracic region of the horse [35,39] has been proposed to be the most important criterion [38] for determining saddle ft. The identification of focal hyperthermic areas along the midline of the thoracic spine and/or hypo/ hyperthermic areas, laterally to the midline along the epaxial musculature, is thought to be indicative of incorrect saddle ft [38].

Focal hyperthermic areas are suggested to represent high friction or pressure points and hypothermic areas are suggested to represent either intense muscle spasm or severe pressure damage/swelling caused by the saddle [38]. The mean temperature differences of >2 .C between the various regions of the ventral aspect of the saddle (saddle panels) have been reported to be indicative of incorrect saddle ft and associated with saddles which showed signs of rocking/bridging [37]. Rocking/ bridging could be an indication that the saddle is too narrow [2].

Thermographic assessments have been used within saddle fitting. The overarching biological assumption appears to be that areas with an increased magnitude in pressure (related to incorrect saddle ft) will alter the heat emitted from the affected region of the thoracic spine as a function of pressure. There is,

however, an apparent lack of evidence specifically quantifying the association between saddle pressures (using an electronic pressure mapping system) and thermographic assessments. Initially, to determine saddle ft, a study has suggested lunging the horse for 20 min in walk, trot and canter whilst wearing a saddle (with a saddle cloth), followed by a thermal scan of the underside of the saddle and then the back [38], followed by a ridden session.

It seems reasonable to expect that the thermal activity will alter as a function of exercise [40,41] hence, making it difficult to differentiate if changes in thermal activity are as a result of saddle ft or as a function of exercise [41]. To the authors’ knowledge, there are no studies which have directly quantified thermal activity and pressure distribution in relation to saddle ft in a group of horses.

The aim of this study was to quantify thermal patterns and saddle pressure distribution in a group of non-lame sports horses ridden by the same rider following a standardised exercise test. It is hypothesised that: (1) there will be differences in thermographic patterns between the baseline and a post lunge exercise test; (2) hyper/ hypothermographic areas will correspond to areas where there is an increased/ decreased magnitude in pressure; (3) there will be differences in thermographic patterns recorded after the lunge (without saddle) test and after the ridden exercise test; (4) there will be thermographic differences between the left and right sides of the underside of the saddle.

2. Materials and Methods This study was approved by the ethics and welfare committee of the first author’s institution, project number URN 2020 1975-2. Informed, written consent was obtained prior to participation in the study. At the time of the study, the rider was free from any injuries and could withdraw their participation from the study at any point.

2.1. Horses A convenience sample of eight adult elite jumping sports horses were recruited who were based at a professional show jumping facility.

The inclusion criteria were that horses were free from lameness as perceived by their owners and in competitive work. Horses were of a similar type and conformation. The day preceding the study, all horses underwent a subjective veterinary assessment performed by an experienced veterinary surgeon which included visual observations in walk

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and trot from both the rear and lateral view as well as a palpatory examination of the thoracolumbar region. No overt signs of lameness or back discomfort/ conditions were observed. On the day of data collection, the horses underwent a physiotherapy assessment assessing the presence or absence of epaxial hypertonicity and pain. In addition, each horse’s gait was quantified whilst trotting in a straight line using a validated sensorbased system (Xsens, Enschede, The Netherlands) [42].

2.2. Rider One male experienced (international showjumping) rider took part in the study, height 1.72 m and a body mass 69 kg. The rider was familiar with all the horses and had been riding them regularly in the time period preceding data collection. At the time of the study, the rider was free from injury and ft to perform.

2.3. Saddles On the day, saddles were assessed independently by five Society of Master Saddlers Qualified Saddle Fitters (SMSQSF). All saddles were checked for ft both statically [43] and dynamically following the Society of Master Saddlers (SMS) published guidelines [44].

2.4. Measuring Systems 2.4.1. Thermal Imaging A FLIR T660 hand-held camera with a standard 25. lens was used for this study. This device has a high thermal detector resolution of 640 × 480 pixels, and high thermal sensitivity or NETD (noise equivalent temperature difference) of <20 mK with a measure­ ment accuracy of ±1–2. . The FLIR T660 is controlled for thermal drift by performing an automatic internal non-uniformity correction (NUC) when the ambient temperature changes considerably.

On the day (December), a wet globe monitor was used to determine ambient temperature which ranged between 4–7 .C and humidity which ranged between 57–70%. Three thermographic scans of the thoracolumbar region were taken at 90. to the subject and at a distance of 1.5 m [45]. Scans were taken from an elevated position (caudal) to the horse.

All thermograms were taken by the same experienced thermography technician.

Protocols (i.e., patient preparation for scanning, enclosed area free from sunlight and draughts, scanning technique— distance and angle) were adhered to, to ensure optimal scanning conditions and thus limit artefacts on the data arising from external factors.

2.4.2. Saddle Kinetics Prior to the study, the pressure mat had been calibrated following manufacturer’s guidelines (Pliance, Novel). On the day, prior to the dynamic measurements, the pressure mat was zeroed without the saddle, girth or rider [1] and was fitted so that the pressure mat was overlaying the horse’s skin and beneath the saddle cloth and saddle as previously described [15–17].

for riding, which included being fitted with a cotton saddle cloth, the horse’s saddle and an anatomically designed girth.

No additional layers were placed beneath the saddle. Finally, each horse was walked (in-hand) to the indoor arena to perform the standardised ridden exercise test.

2.5.3. Standardised Ridden Exercise Test Each horse underwent a standardised 10-

and end points being defined by two cones positioned on the start/end of the testing track. After completion of the ridden exercise test and data collection, the horse was walked for one minute. The girth tension remained unchanged until the horse was presented for scanning.

After the saddle had been removed, horses were scanned as previously described.

2.5.4. Thermal Imaging of the Underside of the Saddle Immediately after the ridden exercise test, the saddle was removed and then placed on a fat surface with the pommel and cantle resting against a vertical breeze blocked wall and a thermal scan was taken.

2.6. Data Collection and Processing Quantitative gait assessment— movement symmetry variables:

Figure 1 - Timelines of the dynamic and ridden exercise test protocol Illustrating the time spent on each rein and gait for both the dynamic unridden exercise test and ridden exercise test. The blue box represents the time when saddle pressure data were collected for trial 1 (T1), T2 and T3 on both the left and right rein in trot and canter.

2.5. Study Protocol 2.5.1. Baseline Thermographic Scan The horse’s rug (blanket) was removed one hour prior to baseline measurement. In this time, the horse was tied up in the stable and was not touched or groomed.

Then, each horse was walked to the thermography area where baseline scans were taken.

2.5.2. Standardised Unridden Dynamic Exercise (Lunge Test) Each horse underwent a standardised 20-min exercise test which consisted of the horse being lunged on a 20 m diameter circle without a saddle, in both a clockwise and anticlockwise direction for set time periods in walk, trot and canter (Figure 1). Horses were lunged by the same handler and were accustomed to the lunging environment in an indoor arena with a uniformed surface. Flat spherical cones were used to mark out the circle circumference and a central cone was positioned in the middle, representing the centre of the circle. After the unridden lunge test, horses were immediately walked to the scanning area. All horses’ backs were scanned following the same protocol as outlined previously. Then, horses were fitted with the Pliance saddle mat as outlined previously and prepared

min warm-up protocol which was called by the same research technician. The warm-up protocol consisted of walk, trot and canter on both the left and right rein (Figure 1). This was followed by a prescribed ridden protocol in trot and canter, during which saddle kinetics were assessed. Data were collected during straight-line locomotion. The speed was determined using a stopwatch, with start

• minimum difference head (HDMin) and pelvis (PDMin): difference between the two minima in vertical (z) displacement observed during the two diagonal stance phases in trot; • maximum difference head (HDMax) and pelvis (PDMax): difference between the two maxima in vertical (z) displacement observed after the two diagonal stance phases in trot; • hip hike difference (HHD): difference between vertical upward movement amplitude of left and right tuber coxae during contra-lateral stance.

Thermographic data: Horse: A grid reference was applied to each thermogram and minimum, maximum and mean temperatures were obtained from each location and processed using Flir software. A mask was applied to areas of the grid which did not correspond to the horse’s back (Figure 3).

Figure 2 -Timeline illustrating the stages of the experiment.

Illustrating the various stages of the experiment including the timepoints at which the thermal scans were taken along with the two exercise tests.

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for the cranial region defined as rows 1–8 and columns A–H (left side) and I–J (right side).

• left-to-right saddle pressure symmetry for the caudal region (left—right) defined as rows 9–16 and columns A–H (left side) and I–J (right side).

Figure 3 - Thermal Grid Reference for the Thoracic Region and Underneath of the Saddle.

Illustrating the thermal grid reference used when quantifying thermal temperatures of the thoracic region (left) and ventral aspect of the saddle (right). A mask (grey area) was applied to areas of the grid which did not correspond to the horse’s back.

Pooled minimum, maximum and mean temperatures (Figure 3): • for the left cranial region defined as LF1, LF2, LF3 and LF4; • for the right cranial region defined as RF1, RF2, RF3 and RF4; • for the left caudal region defined as LF5, LF6, LF7 and LF8; • for the right caudal region defined as RF5, RF6, RF7 and RF8.

Symmetry values: • left–right symmetry for minimum, maximum and mean thermal values of the cra­nial region; • left–right symmetry for minimum, maximum and mean thermal values of the cau­dal region; • front–back symmetry for minimum, maximum and mean thermal values.

Saddle: Thermographic scans were captured of the underside of the saddle.

Using a grid reference applied to each thermogram, minimum, maximum and mean temperatures were obtained from each location and processed using Flir software.

Pooled minimum, maximum and mean temperatures: • for the cranial region defined as L3 and R3; • for the mid region defined as L2 and R2; • for the caudal region defined as L1 and R1.

Symmetry values: • left—right symmetry for minimum, maximum and mean thermal values of the cra­nial region; • left—right symmetry for minimum, maximum and mean thermal values of the mid re­gion;

• left—right symmetry for minimum, maximum and mean thermal values of the cau­dal region; • front—back symmetry for minimum, maximum and mean thermal values.

For the symmetry parameters, values closer to zero represent symmetry between the left and right sides of the body. Positive values indicate increased temperature for the left side, negative values indicate a higher temperature for the right side.

2.7. Saddle Pressure Data The saddle peak and mean (kPa) pressure data were collected from 11 consecutive strides per trial with three repeats totalling 33 ± 3 (mean ± SD) in rising trot and 15 consec­ utive canter strides per trial with three repeats totalling 45 ± 2 in seated canter. The peak and mean pressure (kPa) values for all loaded cells (>2 kPa) were calculated for each stride and stride values were averaged per trial, resulting in three trial-average values per horse and gait. The saddle mat was then split into quadrants, allowing for the quantification of peak and mean pressure differences between the cranial and caudal regions, with positive values indicating increased pressure in the cranial region and negative values indicating increased pressure in the caudal region.

The following peak and mean pressure derived parameters were used for statisti­ cal analysis: • pressures beneath the cranial aspect of the saddle defined as rows 1–8 and columns A–H (left side) and I–J (right side).

• pressures beneath the caudal aspect of the saddle defined as rows 9–16 and columns A–H (left side) and I–J (right side).

• left-to-right saddle pressure symmetry

16

• front-to-back pressure differences between cranial and caudal regions (front-back) defined as cranial (rows 1–8, columns A–J)– caudal (rows 9–16, columns A–J).

For the symmetry parameters, values closer to zero represent symmetry between the left and right sides of the body. Positive values indicate an increased temperature for the left side, negative values indicate a higher temperature for the right side.

2.8. Statistical Analysis Statistical analysis was performed in SPSS (vers. 22, IBM, Armonk, NY, USA).

Six general linear mixed models were implemented for the minimum, maximum and mean thermographic values as outcome variables. Exercise (baseline, post lunge, post ridden) and saddle ft (correct, narrow, wide) were defined as fixed factors and horse was defined as a random factor, with a Bonferroni post hoc analysis being carried out to determine differences between conditions (exercise: baseline, post lunge, post ridden and saddle ft: correct, narrow, wide). The estimated marginal mean (EMM) and standard error (SE) values are presented from the six general mixed model. Saddle pressure data (correct, narrow, wide) and thermal data from the underside of the saddle (front, mid, back) were analysed using an ANOVA with Tukey post hoc analysis and presented as mean and standard deviation (mean ± SD). To check the normality of the data for the general linear mixed models, histograms of residuals were inspected visually and for the ANOVA data, a Shapiro–Wilk normality test was used to determine data distribution.

For all models (saddle pressure and thermography) the significance level was set at p = 0.05. Instead of applying the Bonferroni correction to the significance level, alpha, this study reported the Bonferroni adjusted p-values (p-values based on Fisher’s least significant difference (LSD) multiplied by the number of comparisons carried out). This allows for the assessment of significance with reference to the traditional alpha of 5%, without increasing type II errors.

3. Results

3.3. Thermographic Data of the Thoracic Region

3.1. Horse Inclusion All eight horses were in competitive work (Foxhunter or above, British Show Jump­ing), ranged in height at the withers from 1.60 to 1.70 m with (mean ± SD) of 1.65 ± 0.03 m, had a body mass between 490 and 603 kg (561 ± 23 kg) and were aged nine to 12 years (10 ± 2 years). Each horse underwent a visual lameness evaluation on the day preceding the experiment, performed by an experienced veterinary surgeon. All horses were deemed to be non-lame and did not show any signs of back discomfort. From the objective move­ ment asymmetry measures, horses had (mean ± SD) asymmetry values (mm): HDmin, 4.0 ± 1.4 and HDmax, 5.5 ± 1.0, PDmin 1.3 ± 1.0 and PDmax 4.0 ± 1.1, and HHD 2.4 ± 2.2.

3.2. Saddle Fit Saddles were all jumping type and wool focked. From the static and dynamic assessment, following the SMS guidelines, n = 3 saddles were found to be too narrow, n =3 too wide and n = 2 assessed as a correct ft.

3.3.1. Minimum Temperatures (.C) Time point fixed factor: differences between the minimum temperatures were found for the right cranial region (p = 0.05) and left caudal region (p = 0.04).

For the right cranial region, post hoc analysis showed an increase in minimum temperatures post lunge estimated marginal mean (EMM) and standard error (SE), (21.7 .C, (0.8), (p = 0.05)) compared to baseline (18.7 .C (0.8)) temperatures.

For the left caudal region, an increase in minimum temperatures (23.4 (0.9)), (p = 0.04) compared to baseline (20.6, (0.9)) was found. Post hoc analysis did not identify any differences between post lunge and post ridden exercise (p = 0.51).

Saddle ft fixed factor: no differences were found between saddle conditions (p = 0.29) (Table 1).

3.3.2. Maximum Temperatures (.C) Time point fixed factor: differences were found between the maximum temperatures of the left cranial region (p = 0.0001)

and right cranial region (p = 0.0001).

Differences between the maximum temperatures for the left caudal region (p = 0.001) and the right caudal region (p = 0.001) were found. In all areas, temperatures were higher post lunge and post ridden when compared to the baseline. No differences were found in either the cranial (p = 0.12) or caudal (p = 0.38) symmetry parameters. Saddle ft fixed factor: differences in the maximum temperatures were found for saddle widths (p = 0.05) however, post hoc analysis did not identify any differences between saddle widths (Table 1).

3.3.3. Mean Temperatures (.C) Time point fixed factor: differences were found between the mean temperatures of the left cranial region (p = 0.003) and right cranial region (p = <0.0001). Differences between the mean temperatures for the left caudal region, (p = 0.003) and right caudal region (p = 0.006) were found. In all areas, temperatures were higher post lunge and post ridden when compared to the baseline. No differences were found in either the cranial (p = 0.14) or caudal (p = 0.32) symmetry parameters.

Table 1. Minimum, maximum and mean thermal temperatures of the cranial and caudal regions of the thoracic spine. EMM: Estimated marginal means; SE: standard error.

Correct Saddle Width (◦ C) EMM (SE)

Narrow Saddle Width (◦ C) EMM (SE)

Wide Saddle Width (◦ C) EMM (SE)

Saddle Width Main Effects p Value

-

20.3 (0.9)

20.6 (0.7)

22.2 (0.7)

0.28

-

BL < PL, p = 0.05

20.4 (1.1)

19.1 (0.8)

21.2 (0.8)

0.29

-

0.04

BL<PL, p = 0.04

21.1 (1.3)

22.5 (1.1))

22.9 (1.1)

0.59

-

0.05

-

21.1 (1.7)

21.7 (1.4)

22.5 (1.4)

0.81

-

-

−0.1 (0.6)

1.5 (0.5)

0.9 (0.5)

0.24

-

-

−0.0 (0.4)

0.7 (0.3)

0.4 (0.3)

0.47

-

-

−0.6 (1.0)

−2.2 (0.8)

−0.9 (0.8)

0.45

-

Baseline (BL) (◦ C) EMM (SE)

Post Lunge (PL) (◦ C) EMM (SE)

Post Ridden (PR) (◦ C) EMM (SE)

Exercise Main Effects p-Value

Left Cranial Region

19.9 (0.7)

22.3 (0.7)

20.8 (0.7)

0.12

Right Cranial Region

18.7 (0.8)

21.7 (0.8)

20.3 (0.8)

Left Caudal region

20.6 (0.9)

23.4 (0.9)

22.4 (0.9)

Right Caudal Region

20.4 (1.0)

22.9 (1.0)

21.9 (1.0)

Cranial Region Symmetry (left–right)

1.2 (0.5)

0.5 (0.5)

0.5 (0.5)

Caudal Region Symmetry (left–right)

0.1 (0.2)

0.5 (0.2)

0.5 (0.2)

Difference between cranial and caudal

−1.1 (0.5)

−1.1 (0.5)

−1.5 (0.5)

Pairwise Bonferroni Post Hoc p ≤ 0.05

Pairwise Bonferroni Post Hoc p ≤ 0.05

Minimum Temperature (◦ C)

0.05

0.58 0.29 0.22

Maximum Temperatures (◦ C) Left Cranial Region

26.7 (0.5)

30.9 (0.5)

29.7 (0.5)

<0.0001

BL < PL, p = <0.0001 BL < PR, p = 0.002

28.5 (0.6)

28.1 (0.5)

30.6 (0.5)

0.05

-

Right Cranial Region

26.9 (0.4)

29.7 (0.4)

29.9 (0.4)

<0.0001

BL < PL, p = 0.001 BL < PR, p = <0.0001

28.1 (0.8)

27.9 (0.6)

30.0 (0.6)

0.16

-

Left Caudal region

26.9 (0.4)

29.5 (0.4)

30.1 (0.4)

0.001

BL < PL, p = 0.005 BL < PR, p = 0.002

28.1 (0.6)

28.6 (0.5)

29.6 (0.5)

0.28

-

Right Caudal Region

26.9 (0.4)

29.8 (0.4)

30.1 (0.4)

0.001

BL < PL, p = 0.002 BL < PR, p = 0.001

28.5 (0.6)

28.7 (0.5)

29.6 (0.5)

0.40

-

Cranial Region Symmetry (left–right)

0.7 (0.3)

0.5 (0.3)

−0.1 (0.3)

-

0.4 (0.3)

0.2 (0.3)

0.6 (0.3)

0.71

-

Caudal Region Symmetry (left–right)

−0.0 (0.1)

−0.3 (0.1)

−0.1 (0.1)

0.38

-

−0.3 (0.2)

−0.7 (1.6)

0.2 (0.1)

0.34

-

−0.6 (0.3)

0.9 (0.3)

−0.2 (0.3)

0.006

BL < PL, p = 0.006 PL > PR, p = 0.04

0.3 (0.3)

−0.6 (0.2)

0.6 (0.2)

0.05

-

Difference between cranial and caudal

0.12

Mean Temperatures (◦ C) Left Cranial Region

23.1 (0.6)

26.3 (0.6)

25.2 (0.6)

Right Cranial Region

22.1 (0.6)

26.1 (0.6)

24.9 (0.6)

0.003

BL < PL, p = 0.003 BL < PR, p = 0.03

24.4 (0.9)

24.5 (0.8)

25.7 (0.8)

0.53

-

<0.0001

BL < PL, p ≤ 0.0001 BL < PR, p = 0.006

24.6 (0.9)

23.3 (0.8)

25.3 (0.8)

Left Caudal region

23.3 (0.6)

26.1 (0.6)

26.2 (0.6)

0.29

-

0.003

BL < PL, p = 0.008 BL < PR, p = 0.006

24.2 (1.1)

25.1 (0.8)

26.2 (0.8)

Right Caudal Region

23.3 (0.8)

25.8 (0.8)

26.0 (0.8)

0.40

-

0.006

BL < PL, p = 0.01 BL < PR, p = 0.01

24.5 (1.4)

24.7 (1.1)

26.0 (1.1)

0.67

Cranial Region Symmetry (left–right)

-

0.9 (0.3)

0.1 (0.1)

0.3 (0.30

0.14

-

−0.1 (0.6)

1.2 (0.5)

0.4 (0.5)

0.29

-

Caudal Region Symmetry (left–right)

−0.0 (0.2)

0.2 (0.2)

0.2 (0.2)

0.32

-

−0.2 (0.4)

0.4 (0.3)

0.2 (0.3)

0.45

-

Difference between cranial and caudal

0.7 (0.3)

−0.2 (0.3)

1.0 (0.3)

0.006

BL > PL, p = 0.02 PL < PR, p = 0.008

−0.1 (0.4)

0.9 (0.3)

0.6 (0.3)

0.22

-

17

Saddle ft fixed factor: no differences were found between saddle conditions (p = 0.29) (Table 1).

Table 1. Minimum, maximum and mean thermal temperatures of the cranial and caudal regions of the thoracic spine. EMM: Estimated marginal means; SE: standard error.

Table 1 displays the estimated marginal mean (EMM) and standard error (SE) for the minimum, maximum and mean thermal

temperatures (.C) of the cranial left/right and caudal left/right region of the thoracic spine along with symmetry values for the left and right sides. Thermographic data were collected from each time point: baseline (BL); post lunge (PL); and post ridden (PR) of eight horses. Positive values indicate an increased temperature value for the left side and negative values indicate a higher temperature value for the right side of the thoracic region. For the time point fixed factor, differences in maximum temperatures of the left

cranial (p = 0.0001), right cranial (p = 0.0001), left caudal (p = 0.001) and right caudal area (p = 0.001) of the thoracic region were found. Differences in the mean temperatures of the left cranial (p = 0.003), right cranial (p = 0.0001), left caudal (p = 0.003) and right caudal area (p = 0.006) of the thoracic region were found. In all regions, post hoc analysis showed temperatures post lunge and post ridden were increased when compared to the baseline temperatures (all p = 0.03). Bold indicates significant values p

Table 2. Minimum, maximum and mean thermal temperatures of the underside of the saddle.

Correct Saddle Width (◦ C) Mean ± SD

Narrow Saddle Width (◦ C) Mean ± SD

Wide Saddle Width (◦ C) Mean ± SD

Saddle Width Main Effects (ANOVA) p Value

19.6 ± 2.5

17.8 ± 1.6

19.2 ± 0.6

20.8 ± 1.4

17.2 ± 2.5

Minimum Temperature (◦ C)

Cranial Region (left and right) Mid Region (left and right) Caudal Region (left and right) Cranial Symmetry (Difference between left and right, cranial region)

19.4 ± 0.9

17.2 ± 1.5

Pairwise Tukey Post Hoc p ≤ 0.05

0.04

-

20.1 ± 0.8

0.06

-

20.8 ± 1.5

0.13

-

0.6 ± 1.4

0.2 ± 0.5

−0.7 ± 0.2

0.19

-

Mid Symmetry (Difference between left and right, mid region)

2.7 ± 4.1

0.6 ± 1.5

1.2 ± 1.1

0.62

-

Caudal Symmetry (Difference between left and right, caudal region)

2.2 ± 0.7

−2.3 ± 4.9

0.2 ± 0.4

0.33

-

Cranial-caudal symmetry (Differences between front and back)

−1.2 ± 0.3

−1.0 ± 1.9

−1.1 ± 1.6

0.98

-

Cranial Region (left and right)

23.6 ± 1.6

22.2 ± 0.5

23.1 ± 1.2

24.2 ± 1.6

22.5 ± 0.3

Maximum Temperature (◦ C) Mid Region (left and right) Caudal Region (left and right) Cranial Symmetry (Difference between left and right, cranial region)

23.6 ± 1.6

22.2 ± 0.5

0.32

-

23.1 ± 1.2

0.46

-

23.4 ± 1.4

0.35

-

24.2 ± 1.5

22.9 ± 0.1

23.8± 1.7

0.53

-

0.8 ± 0.7

−0.4 ± 0.2

0.1 ± 0.1

0.04

Correct > narrow, p = 0.03

Caudal Symmetry (Difference between left and right, caudal region)

−0.6 ± 0.8

−0.1 ± 0.9

−0.3 ± 0.3

0.81

-

Cranial-caudal symmetry (Differences between front and back)

−0.4 ± 0.7

0.2 ± 0.7

−0.2 ± 0.3

0.53

-

Mid Region (left and right)

−0.3 ± 0.1

−0.5 ± 0.3

−0.5 ± 0.4

0.89

-

22.6 ± 2.1

20.1 ± 0.8

21.8 ± 1.1

22.8 ± 1.9

20.5 ± 0.6

Mid Symmetry (Difference between left and right, mid region)

Cranial Region (left and right) Mid Region (left and right) Caudal Region (left and right) Cranial Symmetry (Difference between left and right, cranial region)

22.6 ± 2.1

Mean Temperature (◦ C) 20.1 ± 0.8

0.67

-

21.8 ± 1.1

0.16

-

22.4 ± 1.3

0.16

-

23.7± 1.5

21.7 ± 0.2

22.8 ± 1.5

0.30

-

Mid Symmetry (Difference between left and right, mid region)

0.7 ± 0.3

−0.3 ± 0.4

0.1 ± 0.3

0.08

-

Caudal Symmetry (Difference between left and right, caudal region)

0.6 ± 0.7

−0.2 ± 0.4

0.3 ± 0.3

0.26

-

Cranial-caudal symmetry (Differences between front and back)

−0.2 ± 0.5

−0.1 ± 0.3

0.5 ± 0.4

0.21

-

Mid Region (left and right)

−0.1 ± 0.4

−1.4 ± 0.7

−0.6 ± 0.7

0.43

-

Table 2—displaying mean ± S.D. for the minimum, maximum and mean temperatures (◦ C) of the ventral aspect of the saddle taken immediately after a 20-min standardised exercise test. Differences were found in the maximum temperatures of the mid ventral saddle region (p = 0.04). Bold figures represent significant differences p ≤ 0.05. Main effects p-value was obtained by ANOVA.

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(5.5 ± 4.2 kPa). Differences in left-toright differences of the caudal region were found as a function of saddle ft (p = <0.0001). Post hoc analysis showed a greater difference between left and right caudal regions for the narrow saddle (-0.4 ± 0.9 kPa, p = 0.009) compared to the correct (-2.2 ± 1.0 kPa,) and wide saddle (-2.8 ± 0.9 kPa, p = 0.0001). Saddle ft factor: differences were found between the cranial and caudal regions (front– back) (p = 0.05) however, no difference was identified after post hoc analysis (Table 3, Figure 5).

Figure 4 - Thermographs of the underside of the saddle.

Illustrating thermograms of the ventral aspect of the saddle. (A) = correct saddle width, (B) = narrow saddle width and (C) = wide saddle width. Thermographs taken from three horses who had the highest mean and peak saddle pressures (kPa) during the standardised ridden exercise test. For saddle ft fixed factor: differences were found for the minimum temperatures for the cranial region (Figure 2) (p = 0.04).

Differences were found in the asymmetry of the maximum temperatures (.C) for the cranial region with an increase in asymmetry between the left and right cranial regions (Figure 3), for the correct saddle width (0.8 ± 0.7) compared to the narrow saddle width (0.1 ± 0.1, p = 0.03). No differences were found for the remaining parameters (p > 0.06).

= 0.05. Bold figures represent significant differences p = 0.05.

3.4. Thermographic Data of the Underside of the Saddle Saddle fit fixed factor: a general difference between saddle fits was found for the minimum temperature in the underside of the front of the saddle (p = 0.04). However, post hoc analysis did not identify specific pairwise differences between saddle widths. Saddle ft fixed factor: a general difference was found in the maximum temperature for the mid symmetry (difference between the left and right front region) (p = 0.04).

Post hoc analysis showed an increase in asymmetry in the maximum temperature between the left and right front region, for the correct saddle width (0.8 ± 0.7) compared to the narrow saddle width

Differences were found in the maximum temperatures of the mid ventral saddle region (p = 0.04). Bold figures represent significant differences p = 0.05. Main effects p-value was obtained by ANOVA.

3.5. Saddle Pressure Data Saddle ft factor: differences in the mean pressures were found between saddle widths for the right caudal region (p = 0.03). Post hoc analysis showed an increase in the mean pressures for the wide saddle (9.6 ± 2.2 kPa, p = 0.05) when compared to the narrow saddle

Differences in peak pressures were found between saddle widths for the right cranial region (p = 0.03). Post hoc analysis showed an increase in peak pressures for the narrow saddle (53.1 ± 13.2 kPa, p = <0.04) and wide saddle (53.1 ± 13.3 kPa, p = 0.04) compared to the correct saddle width (38.3 ± 2.9 kPa). Saddle ft factor: differences between the cranial and caudal regions (front–back) were found (p = 0.01). Post hoc analysis showed an increase in peak pressures for the narrow saddle (31.6 ± 10.8 kPa, p = 0.008) and wide saddle (26.7 ± 11.7 kPa, p = 0.003) compared to the correct saddle (13.8 ± 4.4 kPa) (Table 3, Figure 5).

4. Discussion Correct saddle ft is considered essential in order to maintain good back health and allow the thoracolumbar region to function without compromising equine locomotion. Attempting to provide an objective approach, thermography has been proposed as a method of quantifying saddle ft [35–40]. Incorrectly fitted saddles, i.e., saddles which are either too wide or too narrow, have been shown to cause focal areas of high pressures in the cranial and caudal thoracic region [2,3].

(0.1 ± 0.1, p = 0.03). No differences were found for the remaining parameters (p > 0.06) Table 2. Minimum, maximum and mean thermal temperatures of the underside of the saddle.

Correct Saddle Narrow Saddle Wide Saddle Saddle Width Pairwise Table 2—displaying mean ± S.D. for the minimum, maximum and mean temperatures (.C) of the ventral aspect of the saddle taken immediately after a 20-min standardised exercise test.

Figure 5 - Pressure Distribution Beneath 3 Saddles Illustrating pressure distribution beneath three saddles: left = correct saddle width; middle = narrow saddle width; right = wide saddle width from three horses who had the highest mean and peak saddle pressures (kPa) during the standardised ridden exercise test. The mean and peak saddle pressure data were collected during straight-line locomotion from 33 trot strides and 45 canter strides from eight horses ridden by the same rider.

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Given the effect of exercise [41] and the change in the location and magnitude of pressure (as a result of saddle width), the idea that thermal activity may be a useful mechanism for identifying incorrect saddle ft [35,38,39] appears of merit, since the magnitude of pressure, as a result of incorrect saddle ft, may affect blood flow due to capillary occlusion [46].

Thermography has been used to scan the underside of the saddle after exercise [35–37] and to quantify differences in thermal patterns between the left and right saddle panels. Thermographic scans

have been performed on the horses’ backs immediately after exercise and thermal symmetry of the back was considered a good indicator of saddle ft [39]. Thermal activity has been reported to be increased on the withers and the midline of the back [35,39] and the contact area of the saddle was reported to be asymmetric [35,47] suggesting incorrect saddle ft.

Whilst these studies provide partial support for the use of thermography as a means of quantifying saddle ft, they are essentially based on the biological assumption that areas with an increased

magnitude of pressure (as a result of saddle ft) will lead to areas of hyperthymic or hypothermic activity as a function of increased or decreased blood flow in the corresponding areas of the horse’s back.

The aim of the present study was to quantify thermographic activity and saddle pressure distribution in a group of non-lame sports horses ridden by the same rider following a standardised thermography protocol including a dynamic exercise test (from here on referred to as: lunge test) and

Table 3. Mean and peak saddle pressures (kPa) during a standardised exercise test.

Correct Saddle Width (kPa) Mean ± SD

Narrow Saddle Width (kPa) Mean ± SD

Wide Saddle Width (kPa) Mean ± SD

Saddle Width Main Effects (ANOVA) p Value

Pairwise Tukey Post Hoc p ≤ 0.05

Mean Saddle Pressures (kPa) Left Cranial Region Right Cranial Region Left Caudal Region Right Caudal Region Cranial Region Symmetry (Left–Right)

17.2 ± 2.4

20.2 ± 6.3

25.1 ± 7.4

0.06

-

0.19

-

5.1 ± 1.1

5.1 ± 3.5

23.9 ± 6.1 6.8 ± 2.2

0.31

-

17.5 ± 2.9

20.4 ± 8.5

7.4 ± 1.6

5.5 ± 4.2

9.6 ± 2.2

0.03

Narrow < wide, p = 0.05

−0.3 ± 1.5

−0.1 ± 2.5

1.1 ± 1.8

0.29

-

Caudal Region Symmetry (Left–Right)

−2.2 ± 1.0

−0.4 ± 0.9

−2.8 ± 0.9

<0.0001

Difference between Cranial and Caudal regions (front–back)

Correct > Narrow, p = 0.009 Narrow < wide, p ≤ 0.0001

11.1 ± 1.3

15.0 ± 5.6

16.2 ± 5.1

0.05

-

Peak Saddle Pressures (kPa) Left Cranial Region

36.6 ± 2.8

51.5 ± 7.8

51.1 ± 18.1

0.05

-

Right Cranial Region

38.3 ± 2.9

53.1 ± 13.2

53.1 ± 13.3

0.03

Correct < narrow, p = 0.04 Correct < wide p = 0.04

Left Caudal Region

21.7±5.1

-

27 ± 7.2

0.20

-

Cranial Region Symmetry (Left—Right)

21.1 ± 8.8

23.4 ± 6.1

0.62

25.5 ± 3.1

20.4 ± 6.9

−1.7 ± 1.6

−1.6 ± 9.2

−2.1 ± 6.7

0.99

-

Caudal Region Symmetry (Left—Right)

−3.8 ± 5.1

−0.5 ± 2.9

−3.8 ± 1.9

0.09

-

0.01

Correct < narrow, p = 0.008 Correct < wide p = 0.003

Right Caudal Region

Difference between Cranial and Caudal regions (front–back)

13.8 ± 4.4

31.6 ± 10.8

26.7 ± 11.7

Displaying mean ± S.D. for the mean and peak saddle pressures (kPa) of the cranial and caudal regions of the saddle. The mean and peak saddle pressure data were collected during straight-line locomotion from 33 trot strides and 45 canter strides from eight horses ridden by the same rider. The mean and peak saddle pressures were obtained for each stride and averaged across each trial. Tukey post hoc analysis was performed with a significance level set at p ≤ 0.05. A positive value indicates an increased pressure value for the left side/cranial region, and a negative value indicates increased pressure value in the right side/caudal region. An increase in mean pressures (kPa) for the wide saddle (p ≤ 0.05) when compared to the narrow saddle was found. Differences between the cranial and caudal regions (front–back) showed an increase in peak pressures for the narrow saddle (p = 0.008) and wide saddle (p = 0.003) compared to the correct saddle (Table 3).

Bold indicates significant values p ≤ 0.05. Main effects p-value was obtained by ANOVA.

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a standardised ridden test. The authors appreciate that this study is limited by its sample size—in particular with respect to saddle ft— and caution should hence be taken when generalising the findings being presented here. However, to the authors’ knowledge, this is the frst study to quantify thermal activity and saddle pressure distribution in the same horses.

The findings being presented here should be used to advance our understanding of the applications of thermography and its limitations within saddle fitting and provide a basis for future research.

In the current study, all thermographic scans were performed by a trained and experienced thermographer. Camera angle and distance from the horses was standardised to limit error; a 20. change in camera angle relative to the object has been shown previously not to affect thermal data [45]. The horse’s thoracic area was not clipped, and the ambient temperature varied (3 .C) and this should be considered when interpreting the results. However, in accordance with scanning requirements, strict protocols (i.e., patient preparation for scanning, enclosed area free from sunlight and draughts, scanning technique—distance and angle) were adhered to, to ensure optimal scanning conditions and thus limit artefacts on the data arising from external factors.

To determine whether any changes in thermal activity were observed as a result of exercise, or the addition of the saddle+rider, a lunge test was performed on a 20 m circle without the saddle or rider prior to the ridden exercise (with saddle+rider). In accordance with our frst experimental hypothesis, differences were found between the baseline thermographic and thermal scans obtained directly after lunging. Thermal activity in all regions of the thoracic area (left/right cranial and left/right caudal) (Table 1) were increased as a function of exercise. It seems reasonable to expect such an increase given the physiological response to exercise [41] and increased blood flow to muscles. Across all horses, the minimum, maximum and mean temperatures obtained during the baseline ther­ mogram were highest in the cranial–mid (T10–T14) region of the thoracic spine compared to the caudal region [41]. The reason for this warrants further investigation.

Lunging a horse whilst wearing a saddle has been suggested as a method to evaluate saddle ft [38]. In that study, the underside of the saddle was assessed immediately after lunge exercise [38].

In the current study, we chose not to ft a saddle while the horses were being lunged as our aims were (1) to investigate whether there is an increase in thermal

activity as a function of exercise and (2) to determine any differences—induced by adding a saddle+rider—between the lunge test and the standardised ridden exercise test.

In the current study, saddle ft was assessed by fve SMS qualifed saddle ftters following the SMS’s static and dynamic saddle fitting guidelines. Saddles were found to vary in ft, with the majority of saddles being classified as incorrectly fitting, with three saddles assessed as a wide ft and three saddles assessed as a narrow ft. The inclusion of horses with varying saddle ft provided a “real life” opportunity to compare thermography and saddle pressure measurements to describe saddle ft. In order to limit the influence of inter-horse differences, further studies should be conducted with saddles of different ft used in the same horses in a repeated measures design [2,3,5–8].

Being aware of the consequences of the small sample size, in particular in relation to a reduced power to detect small differences, an equivalence test [48] for the thermographic symmetry parameters obtained after lunging and after ridden exercise (see Table 1) was performed following the procedure, implementing two one-sided tests of equivalence for paired-samples (TOST-P) [48]. We chose a tolerance value of ±2., effectively considering changes between post-lunge and post-ridden exercise of less than that amount to be evidence of no change. This tolerance level is consistent with [37]. All one-sided tests indicated that the postlunge and post-ridden thermographical symmetry outputs can be seen as equivalent (all p = 0.027).

Compared to a correctly fitted saddle (determined by the lowest overall saddle force), both the magnitude and location of pressure have been shown to change when horses were ridden on a treadmill in walk and trot [3]. In a narrow saddle, increased pressures were found in the caudal third of the saddle. In the wide and very wide saddles, high pressures were reported for the middle transversal third of the saddle, close to the midline of the equine spine [3]. In an over-ground study, in trot and canter, when ridden in a saddle which was one width fitting wider than correct width fitting (determined by the SMS static and dynamic guidelines and lowest overall force), areas of high pressures were found in the cranial region of the saddle [2]. Measurable concavities have been reported in the epaxial musculature in the region of the 13th thoracic vertebra after 20 min of exercise in a wide saddle, as a function of the magnitude of pressure and its relationship with the epaxial musculature [2]. In the

21

current study, during ridden exercise, the saddles which were classified as a correct saddle ft showed a uniformed pressure distribution. In the saddles classified as too narrow and too wide, the magnitude of pressure was increased in the cranial region of the saddle (difference between the cranial and caudal peak pressures: correct 13.8 ± 4.4 kPa; narrow 31.6 ± 10.8; wide 26.7 ± 11.7). The magnitude of the peak and mean pressure in these cases exceeded the pressures that have been suggested to cause back discomfort [49]. Our findings, in a small sample of horses and saddles, are in accordance with previous studies indicating increased magnitude of pressure in the cranial region when ridden in a wide saddle [2,3].

To limit the effect that different riders may have on saddle pressures (and consequently potentially on thermal activity) we used one experienced show jumping rider [16]. Further studies should ideally make use of a repeated measures design with respect to both saddle and rider, i.e., generating multiple assessments with different saddles and riders in the same horses. In the current study, when using the narrow saddle, the magnitude of pressure was increased in the cranial region, which is different to the findings of previous studies [2,3]. This might be explained by the rider’s position and in particular the rider’s posture indicative of a forward shift of the centre of mass.

It may be speculated that this position applies more pressure on the cranial region of the back.

High saddle pressures may lead to hyperthermic or hypothermic activity as a result of altered blood flow, leading to capillary restriction due to increased pressure [46]. In accordance with our second hypothesis associating hyper/ hypothermographic areas with areas of increased/decreased magnitude in pressure, areas of high pressures were found in the cranial region for the narrow and wide saddles, but this was not reflected in thermal activity in the cranial (left/right) region or thermal symmetry parameters of the cranial and caudal regions of the thoracic region. We therefore refute our second hypothesis, that areas with increased magnitude of pressure would result in hyper-and/ or hypothermic areas. Hyperthermic activity has been suggested to represent high friction or pressure points and hypothermic activity has been suggested to represent intense muscle spasm or severe pressure damage/swelling caused by the saddle [38].

In humans, pressures at surface level penetrate the tissue until they converge on the underlying bony structures, reaching higher values than at the level of

the skin surface [50]. The mean capillary pressure in humans is approximately 3.33 kPa [51]. When an external pressure is applied, it increases to >4.26 kPa, at which point blood vessels will restrict and become occluded. In the equine model, saddle pressures are transient and alter with limb movement [6,52–54]. It is generally accepted that pressures which are prolonged and exceed mean pressures >11 kPa and peak pressures > 30 kPa [15] are thought to be undesirable and have the potential to cause back discomfort.

It seems reasonable to assume that the magnitude of mean (±SD) and peak (±SD) pressures measured in the current study, which for the narrow saddle were 20.2 (±6.3) kPa and 53.1 (±13.2) kPa, respectively, for the wide saddle were 25.1 (±7.4) kPa and 53.1 (±13.3) kPa, respectively, could affect capillary pressure and consequently thermal activity.

No differences were found in thermal activity between the unridden and unsaddled lunge test and the ridden test, and our additional equivalence testing indicated that these conditions are equivalent based on a +/-2. tolerance level. This highlights the importance of performing a standardised unridden dynamic exercise test without a load (saddle) to ensure that exercise-induced changes in thermal patterns are not misinterpreted as being a result of saddle ft [38]. The increase in thermal activity in the thoracic region found in the present study was as a function of exercise and not saddle ft. We hence refute our third hypothesis, which predicted differences in thermographic patterns between the lunge test without a saddle and the ridden exercise test. Our study highlights that, when conducting a dynamic saddle ft test (which necessitates the horse to exercise), the challenges of distinguishing between changes in thermal patterns solely related to exercise and changes related to saddle ft should not be underestimated.

Lastly, thermographs of the underside of the saddle have been proposed as a method which is sensitive enough to determine saddle ft [35–37] with differences >2 .C repre­senting incorrect saddle ft [37]. In the current study, the narrow and wide saddles were classified as an incorrect ft based on the SMS Saddle Fitting Guidelines. The thermograms of the underside of the saddle did not appear to reflect the findings of the saddle ft as­sessment: for both the wide and narrow saddle, mean and maximum thermal asymmetry between the left and right sides were <0.5 .C despite the high pressures observed during ridden exercise. Minimum asymmetry temperature values for the narrow saddle were -2.3 (±4.9) .C, which would appear to be of significance [37]. However, this

asymmetry was observed in the caudal region which, from our kinetic saddle data, was not the region of the back experiencing high dynamic pressures.

In contrast, in the cranial region, with high pressures observed, the thermal asymmetry was 0.2 (±0.5) .C. Therefore, based on the findings presented here, we refute our fourth hypothesis and recommend that caution is taken when applying thresholds and basing saddle fitting results solely on thermograms of the underside of the saddle.

5. Conclusions This study has investigated the relationship between saddle pressures and thermal activity in the context of saddle fitting. Our findings did not provide evidence supporting a direct link between thermal activity and areas with an increased magnitude of pressure under the saddle. We did, however, find consistent exercise-induced changes in thermal activity. This complicates the use of thermal imaging for assessing dynamic saddle fitting.

Author Contributions: Conceptualization, R.M.-G., T.P., V.F., K.K. and M.F.; methodology, R.M.-G., T.P., V.F., K.K. and M.F.; software, T.P., M.F., H.M., K.K.; formal analysis, R.M.-G., T.P., V.F., K.K.; investigation, R.M.-G., T.P., V.F., D.F., K.K. and M.F.; data curation, R.M.-G., T.P., V.F., K.K. and M.F.; R.M.-G. and T.P.; writing—review and editing, R.M.-G., T.P., H.M., K.K., D.F., M.F. and V.F.; visualization, R.M.-G. and T.P.; project administration, R.M.-G. and V.F.; funding acquisition, D.F. All authors have read and agreed to the published version of the manuscript.

Funding: This research received no external funding with the exception that the open access publica­tion was funded by the Society of Master Saddlers.

Institutional Review Board Statement: This study was approved by the ethics and welfare commit­ tee of the first author’s institution, project number URN 2020 1975-2. Informed, written consent was obtained prior to participation in the study. At the time of the study, all riders were free from any injuries and could withdraw their participation from the study at any point.

Informed Consent Statement: Informed consent was obtained from the rider involved in the study. The rider could withdraw their participation and that of their horses at any point.

Acknowledgments: The authors thank the owners of the horses, the rider and venue for hosting the study along with

22

the research assistants Anna Lawson, Antonia Bealby, Beatrice Blakeman, John Hirrell, Mark Watson, Ruth Wyatt. Thanks to the Society of Master Saddlers (SMS) for providing the funding to allow the publication as open access.

Conficts of Interest: H.M. and K.K. work with Vet-IR—thermography consultancy.

M.F., D.F. and V.F. are SMS qualifed saddle ftters. T.P. is owner of EquiGait Ltd. providing gait analysis products and services. R.M.-G. is director of Centaur Biomechanics.

References 1. Mackechnie-Guire, R.; MackechnieGuire, E.; Fisher, M.; Mathie, H.; Bush, R.; Pfau, T.; Weller, R. Relationship Between Saddle and Rider Kinematics, Horse Locomotion, and Thoracolumbar Pressures in Sound Horses. J. Equine Vet. Sci. 2018, 69, 43–52. [CrossRef] 2. Mackechnie-Guire, R.; MackechnieGuire, E.; Fairfax, V.; Fisher, D.; Fisher, M.; Pfau, T. The Effect of Tree Width on Thoracolumbar and Limb Kinematics, Saddle Pressure Distribution, and Thoracolumbar Dimensions in Sports Horses in Trot and Canter. Animals 2019, 9, 842. [CrossRef] [PubMed] 3.

Meschan, E.M.; Peham, C.; Schobesberger, H.; Licka, T.F. The influence of the width of the saddle tree on the forces and the pres-sure distribution under the saddle. Vet. J. 2007, 173, 578–584. [CrossRef] 4. Clayton, H.M.; Hampson, A.; Fraser, P.; White, A.; Egenvall, A. Comparison of rider stability in a fapless saddle versus a conven-tional saddle. PLoS ONE 2018, 13, e0196960. [CrossRef] [PubMed] 5. Martin, P.; Cheze, L.; Pourcelot, P.; Desquilbet, L.; Duray, L.; Chateau, H. Effects of Large Saddle Panels on the Biomechanics of the Equine Back During Rising Trot: Preliminary Results. J. Equine Vet. Sci. 2017, 48, 15–22. [CrossRef] 6. Murray, R.; Guire, R.; Fisher, M.; Fairfax, V. Reducing Peak Pressures Under the Saddle Panel at the Level of the 10th to 13th Thoracic Vertebrae May Be Associated With Improved Gait Features, Even When Saddles Are Fitted to Published Guidelines. J. Equine Vet. Sci. 2017, 54, 60–69. [CrossRef] 7. Murray, R.; Mackechnie-Guire, R.; Fisher, M.; Fairfax, V. Reducing peak pressures under the saddle at thoracic vertebrae 10–13 is associated with alteration in jump kinematics. Comp.

Exerc. Physiol. 2018, 14, 239–247.

[CrossRef]

8. Murray, R.; Mackechnie-Guire, R.; Fisher, M.; Fairfax, V. Could Pressure Distribution Under Race-Exercise Saddles Affect Limb Kinematics and Lumbosacral Flexion in the Galloping Racehorse?

J. Equine Vet. Sci. 2019, 81, 102795.

[CrossRef] 9. Belock, B.; Kaiser, L.J.; Lavagnino, M.; Clayton, H.M. Comparison of pressure distribution under a conventional saddle and a tree-less saddle at sitting trot. Vet. J. 2012, 193, 87–91. [CrossRef] 10. Clayton, H.M.; O’Connor, K.A.; Kaiser, L.J. Force and pressure distribution beneath a conventional dressage saddle and a treeless dressage saddle with panels.

Vet. J. 2014, 199, 44–48. [CrossRef] 11. Latif, S.N.; Von Peinen, K.; Wiestner, T.; Bitschnau, C.; Renk, B.; Weishaupt, M.A. Saddle pressure patterns of three different training saddles (normal tree, fexible tree, treeless) in Thoroughbred racehorses at trot and gallop. Equine Vet. J. 2010, 42, 630–636. [CrossRef] [PubMed] 12. Harman, J. Tack and Saddle Fit. Vet. Clin. Am Equine Pract. 1999, 15, 247–261.

[CrossRef] 13. Greve, L.; Dyson, S.; Pfau, T. Alterations in thoracolumbosacral movement when pain causing lameness has been improved by diagnostic analgesia. Vet. J. 2017, 224, 55–63. [CrossRef] [PubMed] 14. Greve, L.; Dyson, S.J. An investigation of the relationship between hindlimb lameness and saddle slip. Equine Vet. J. 2013, 45, 570–577. [CrossRef] [PubMed] 15. Bystr, A.; Stalfelt, A.; Egenvall, A.; Von Peinen, K.; Morgan, K.; Roepstorff, L. Influence of girth strap placement and panel focking material on the saddle pressure pattern during riding of horses. Equine Vet. J. 2010, 42, 502–509.

[CrossRef] [PubMed] 16. Peham, C.; Licka, T.; Schobesberger, H.; Meschan, E. Influence of the rider on the variability of the equine gait. Hum. Mov. Sci. 2004, 23, 663–671. [CrossRef] 17. Dyson, S.; Carson, S.; Fisher, M. Saddle fitting, recognising an ill-fitting saddle and the consequences of an illfitting saddle to horse and rider. Equine Vet. Educ. 2015, 27, 533–543. [CrossRef] 18. de Cocq, P.; Clayton, H.M.; Terada, K.; Muller, M.; van Leeuwen, J.L. Usability of normal force distribution measurements to evalu-ate asymmetrical lo.ading of the back of the horse and different rider positions on a standing horse. Vet. J. 2009, 181, 266–273. [CrossRef] [PubMed] 19. de Cocq, P.; van Weeren, P.R.; Back, W. Saddle pressure measuring: Validity,

reliability and power to discriminate between dif-ferent saddle-fts. Vet. J. 2006, 172, 265–273. [CrossRef] 20. Fruehwirth, B.; Peham, C.; Scheidl, M.; Schobesberger, H. Evaluation of pressure distribution under an English saddle at walk, trot and canter. Equine Vet. J. 2010, 36, 754–757. [CrossRef] 21. Kotschwar, A.; Baltacis, A.; Peham, C. The influence of different saddle pads on force and pressure changes beneath saddles with excessively wide trees. Vet. J. 2010, 184, 322–325. [CrossRef] 22. Kotschwar, A.B.; Baltacis, A.; Peham, C. The effects of different saddle pads on forces and pressure distribution beneath a fitting saddle. Equine Vet. J. 2010, 42, 114–118. [CrossRef] 23. Alvarez, C.B.G.; Wennerstrand, J.; Bobbert, M.F.; Lamers, L.; Johnston, C.; Back, W.; Van Weeren, P.R. The effect of induced forelimb lameness on thoracolumbar kinematics during treadmill locomotion. Equine Vet. J. 2007, 39, 197–201. [CrossRef] 24. Buchner, H.H.F.; Schamhardt, H.; Barneveld, A. Head and trunk movement adaptations in horses with experimentally induced fore-or hindlimb lameness.

Equine Vet. J. 1996, 28, 71–76. [CrossRef] 25. Gomez Alvarez, C.B.; Bobbert, M.F.; Lamers, L.; Johnston, C.; Back, W.; van Weeren, P.R. The effect of induced hindlimb lameness on thoracolumbar kinematics during treadmill locomotion.

Equine Vet. J. 2008, 40, 147–152.

[CrossRef] 26. Greve, L.; Dyson, S.J. The interrelationship of lameness, saddle slip and back shape in the general sports horse population. Equine Vet. J. 2014, 46, 687–694. [CrossRef] [PubMed] 27. Landman, M.A.A.M.; de Blaauw, J.A.; Hofand, L.J.; van Weeren, P.R. Field study of the prevalence of lameness in horses with back problems. Vet. Rec. 2004, 155, 165–168. [CrossRef] [PubMed] 28. Keegan, K.G.; Dent, E.V.; Wilson, D.A.; Janicek, J.; Kramer, J.; Lacarrubba, A.; Walsh, D.M.; Cassells, M.W.; Esther, T.M.; Schiltz, P.; et al. Repeatability of subjective evaluation of lameness in horses. Equine Vet. J. 2010, 42, 92–97.

[CrossRef] [PubMed] 29. Keegan, K.G.; Wilson, D.A.; Wilson, D.J.; Smith, B.; Gaughan, E.M.; Pleasant, R.S.; Lillich, J.D.; Kramer, J.; Howard, R.D.; Bacon-Miller, C.; et al. Evaluation of mild lameness in horses trotting on a treadmill by clinicians and interns or residents and correlation of their assessments with kinematic gait analysis. Am. J. Vet. Res.

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1998, 59, 1370–1377.

30. Hewetson, M.; Christley, R.M.; Hunt, I.D.; Voute, L.C. Investigations of the reliability of observational gait analysis for the assessment of lameness in horses.

Vet. Rec. 2006, 158, 852–858. [CrossRef] 31. Parkes, R.S.V.; Weller, R.; Groth, A.M.; May, S.; Pfau, T. Evidence of the development of ‘domain-restricted’ expertise in the recognition of asymmetric motion characteristics of hindlimb lameness in the horse. Equine Vet. J. 2009, 41, 112–117. [CrossRef] [PubMed] 32. McCracken, M.J.; Kramer, J.; Keegan, K.G.; Lopes, M.; Wilson, D.A.; Reed, S.K.; Lacarrubba, A.; Rasch, M. Comparison of an inertial sensor system of lameness quantifcation with subjective lameness evaluation. Equine Vet. J. 2012, 44, 652– 656. [CrossRef] 33. Soroko, M.; Howell, K. Infrared Thermography: Current Applications in Equine Medicine. J. Equine Vet. Sci. 2018, 60, 90–96.e2. [CrossRef] 34. Schweinitz, D.V. Thermographic diagnosis in equine back pain. Vet. North Clin. N. Am. Equine Pract. 1999, 15, 161– 177. [CrossRef] 35. Arruda, T.Z.; Brass, K.E.; De La Corte, F.D. Thermographic Assessment of Saddles Used on Jumping Horses. J. Equine Vet. Sci. 2011, 31, 625–629. [CrossRef] 36. Soroko, M.; Cwynar, P.; Howell, K.; Yarnell, K.; Dudek, K.; Zaborski, D. Assessment of Saddle Fit in Racehorses Using Infrared Thermography. J. Equine Vet. Sci. 2018, 63, 30–34. [CrossRef] 37. Soroko, M.; Zaborski, D.; Dudek, K.; Yarnell, K.; Górniak, W.; Vardasca, R. Evaluation of thermal pattern distributions in racehorse saddles using infrared thermography. PLoS ONE 2019, 14, e0221622. [CrossRef] 38. Turner, T.A.; Waldsmith, J.K.; Wilson, J.H. How to assess saddle ft in horses.

Proc. Am. Assoc. Equine Pract. 2004, 50, 196–201.

39.

Masko, M.; Krajewska, A.; Zdrojkowski, L.; Domino, M.; Gajewski, Z. An application of temperature mapping of horse’s back for leisure horse-ridermatching. Anim. Sci. J. 2019, 90, 1396– 1406. [CrossRef] [PubMed] 40. Soroko, M.; Jodkowska, E.; Zablocka, M. The Use of Thermography to Evaluate Back Musculoskeletal Responses of Young Racehorses to Training. Thermol. Intern.

2012, 22, 114.

41. Witkowska-Pilaszewicz, O.; Masko, M.; Domino, M.; Winnicka, A. Infrared

Thermography Correlates with Lactate Concentra-tion in Blood during Race Training in Horses. Animals 2020, 10, 2072. [CrossRef] 42. Pfau, T.; Witte, T.H.; Wilson, A.M. A method for deriving displacement data during cyclical movement using an inertial sensor. J. Exp. Biol. 2005, 208, 2503–2514.

[CrossRef] [PubMed] 43. Guire, R.; Weller, R.; Fisher, M.; Beavis, J. Investigation Looking at the Repeatability of 20 Society of Master Saddlers Qualifed Saddle Fitters’ Observations During Static Saddle Fit. J. Equine Vet. Sci. 2017, 56, 1–5. [CrossRef] 44. Guilds and City. Certifcate in Saddle Fitting, in Association with the Society of Master Saddlers; City and Guilds, NPTC: London, UK. Available online: http://tinyurlcom/y82f9at22007:4750-80 (accessed on 30 September 2020).

46. von Peinen, K.; Wiestner, T.; von Rechenberg, B.; Weishaupt, M.A. Relationship between saddle pressure measurements and clinical signs of saddle soreness at the withers. Equine Vet. J Suppl. 2010, 38, 650–653. [CrossRef] 47. Dantas, F.; Duarte, M.; Marins, J.; Fonseca, B. Thermographic assessment of saddles used in Mangalarga Marchador horses. Arq. Bras. de Med. Vet. e Zootec.

2019, 71, 1165–1170. [CrossRef] 48. Mara, C.A.; Cribbie, R.A. PairedSamples Tests of Equivalence. Commun.

Stat.-Simul. Comput. 2012, 41, 1928–1943.

[CrossRef] 49. Nyikos, S.; Von Rechenberg, B.; Werner, D.; Mler, J.A.; Buess, C.; Keel, R.; Kalpen, A.; Vontobel, H.-D.; Von Plocki, K.A.; Auer,

51. Chang, W.L.; Seigreg, A.A. Prediction of ulcer formation on the skin. Med. Hypotheses 1999, 53, 141–144. [CrossRef] [PubMed] 52. Mackechnie-Guire, R.; Fisher, M.; Pfau, T. Effect of a Half Pad on Pressure Distribution in Sitting Trot and Canter beneath a Saddle Fitted to Industry Guidelines. J. Equine Vet. Sci. 2021, 96, 103307. [CrossRef] [PubMed] 53. Mackechnie-Guire, R.; MackechnieGuire, E.; Bush, R.; Fisher, D.; Fisher, M.; Weller, R. Local Back Pressure Caused by a Training Roller During Lunging With and Without a Pessoa Training Aid. J. Equine Vet. Sci. 2018, 67, 112–117. [CrossRef] 54. Murray, R.; Guire, R.; Fisher, M.; Fairfax, V. A Bridle Designed to Avoid Peak Pressure Locations under the Headpiece and Noseband Is Associated with More Uniform Pressure and Increased Carpal and Tarsal Flexion, Compared with the Horse’s Usual Bridle. J. Equine Vet. Sci. 2015, 35, 947–955. [CrossRef]

Target the inflammation and heat build up in horses legs after exercise or injury, with cooling and compression from

45. Westermann, S.; Buchner, H.; Schramel, P.; Tichy, T.; Stanek, C. Effects of infrared camera angle and distance on measurement and reproducibility of thermographically determined temperatures of the distolateral aspects of the forelimbs in horses. J. Am. Vet. Med. Assoc. 2013, 242, 388–395. [CrossRef] [PubMed]

J.A. Measurements of saddle pressure in conjunction with back problems in horses.

Pferdeheilkunde Equine Med. 2005, 21, 187–198. [CrossRef]

50. Le, K.M.; Madsen, B.L.; Barth, P.W.; Ksander, G.A.; Angell, J.B.; Vistnes, L.M. An in-depth look at pressure sores using monolithic silicon pressure sensors.

Plast. Reconstr. Surg. 1984, 74, 745–754.

[CrossRef]

Target the inflammation and heat build up in horses legs after exercise or injury, with cooling and compression from

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Horses Inside Out Conference : 22nd and 23rd February 2020 Holywell Conference Centre, Loughborough University, England Sue Palmer MCSP, IHRA, ACPAT and RAMP Chartered Physiotherapist, BHSAI CPD hours: 16

Speakers: Gillian Higgins

David Kempsell

Dr Andrew Hemmings

Mark Johnson

Vibeke Elbrond

Dr Seth O’Neill

Dr Sue Dyson

Richard Hepburn

D

id you know that if you rest for 5 days after a tendon injury rather than keep moving appropriately, you could delay your healing for 3 weeks? Did you know that the liver is connected to the jaw?

Gillian Higgins and the Horses Inside Out team presented their annual Horses Inside Out conference on Saturday 22nd and Sunday 23rd February at the Holywell Conference Centre, Loughborough University, and I was lucky enough to be one of the attendees. The presenters, as always, were world class. The theme of this year’s conference was ‘Anatomy in Action’, with a particular focus on the role of fascia, tendons, ligaments, muscles and internal anatomy, as well as hoof anatomy, the thoracic sling, an examination of lameness diagnosis, and how to hel horses struggling with poor performance (yep, you’re absolutely right if you’re thinking that’s a lot of information to cover!).

Throughout each of the breaks and through lunch the presenters were available for individual questions (or perhaps they were cornered by audience members!), and Mark Johnson in particular invited us to go and see the hoof specimens and the specialised shoe that he’d brought with him. I’ve been to several Horses Inside Out conferences, and one of the things that Gillian and her team have done in response to feedback is to make the breaks much longer than they used to be, which allows more time for catching up with friends, browsing the stalls, reading the scientific posters and questioning their authors, blowing your mind at the stunning anatomical displays, and of course questioning the presenters.

Saturday 22nd February Gillian Higgins Gillian opened the conference at 8.50am with a discussion of anatomy in action. I learned, to my surprise, that Eadweard Muybridge created what is believed to be the world’s first moving picture, and it was of a galloping horse! He was working to

answer the question of whether all four feet of the horse were off the ground during a trot stride. Cameras at the time did not have a fast enough shutter speed to capture movement, and Muybridge worked to change this. He invented the ‘zoopraxiscope’ to present 12 images of a galloping horse, hence the ‘moving picture’.

Gillian is releasing her own catalogue of ‘Anatomy in Action’ this summer, a unique fold out photographic anatomical catalogue of equine movements illustrating the versatility, strength, beauty and athletic prowess of the horse in motion, available this summer. Judging by the quality of her current books and DVDs, this will be one to look out for.

Celeste Wilkins

balancing structures. This helps to explain the connections between one part of the body and another, both during standing and in motion, and may also explain how compensatory mechanisms develop and show up in the body. To help describe the importance of fascia in the body, Vibeke referenced Tom Myers, author of Anatomy Trains, as saying ‘We are one big muscle in 600 different bags’.

Take home messages: “We are one big muscle in 600 different bags” Tom Myers Warm up and cool down is important in terms of fascia.

Dr Vibeke Elbrond: Understanding locomotor myofascial connections

The myofascial kinetic lines balance the body in a 3D network in standing and in motion.

Associate Professor in Anatomy and Biochemistry at the Department of Veterinary and Animal Science with a PhD in Anatomy and Physiology and a research field in biomechanics / functional anatomy with a focus on the functionality and integrity of fascia.

David Kempsell: The thoracic sling connection

Vibeke’s talk was titled ‘Understanding Locomotor Myofscial Connections’. ‘Myo’ is muscle, and ‘fascia’ is a connective tissue that is spread throughout the body. As a Chartered Physiotherapist, I have long been fascinated by fascia, and I manipulate it on a daily basis to improve the comfort and performance of the horses I treat.

Fascia has many roles, including the force transmission of muscle contractions onto tendons, bones and other muscles, shock absorption, and the exchange of kinetic and elastic energy. The ‘myofascial lines’ are connections of muscle and fascia that, on dissection, have been shown to travel from one part of the body to another.

Think of it a bit like a train, with the muscles as carriages and the connections as the fascia. There have been found to be many different myofascial lines, which provide a 3D full body network of

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Saddler and Managing Director of Firth Thought Equine Ltd, which bases it’s products on scientific research and has revolutionised the saddle industry.

The thoracic sling in the horse is the set of muscles, tendons, fascia and connective tissue connecting the horse’s front legs to the rest of it’s body. This is important since the hrose doesn’t have a collar bone. David introduced us to the idea of asymmetry in the horse being as a result of shorter muscles on one side of the thoracic sling than on the other. This, he postulates, leads to shorter leg length on one side (usually the right fore), which in turn affects the balance of the rib cage.

He took us through one of his many case studies where he has measured the pressures under the saddle in the ridden horse whilst making adjustments to leg length (by placing pads under the shorter foot), or to the saddle fit (by increasing or decreasing the air in the pads front / back / left / right as appropriate).

Take home messages: Which comes first – the horse or the rider???

In David’s tests, he found that 95% of riders had more weight through their left seatbone, which in turn means their bodyweight is tipped to the right.

We need more research into the musculoskeletal imbalance of riders, and how this affects their weight distribution in the saddle.

Dr Seth O’Neill: Tendons and tendinopathy management With his PhD ‘A biomechanical approach to Achilles tendinopathy management’, Seth, a Chartered Physiotherapist, has clinical and research interests focusing around tendon disorders, in particular lower limb tendinopathy and rupture, and is particularly interested in improving treatments and preventative strategies.

I don’t suppose I’ll ever forget the video clip that Seth showed of a person snapping their achilles tendon! It makes a noise like a gun going off, and is really not nice to watch!

Tendinopathy (damage to the tendon) generally happens over time. The research shows clearly that damage occurs when ‘loading is excessive for the maintenance of tissue homeostasis’. Basically, this means that damage occurs when the rate the body is ‘wearing’ is faster than that at which it is ‘repairing’. Over time, the overworked tendon effectively degenerates. Ultimately the tendon’s structure and material properties change and the tendon becomes less resilient.

Because of this reduced resilience, injury is then more likely to occur even under normal work load. This provides important information on how we can approach exercise and training to give our bodies the best chance of maintaining healthy tendons, and trainers can provide programs that are informed by science.

Since the structure of the horse’s tendon is similar to that of a human tendon, the research can also be applied to training our horses.

Take home messages: Prevention is better than cure.

Overload is the predominant factor in developing tendinopathy in humans.

If you rest completely for five days after a tendon injury, rather than keeping moving at an appropriate level for your injury, you could delay your healing by up to three weeks!

Dr Andrew Hemmings: Training the brain Principal Lecturer in Equine Science and head of department (Equine Management and Science) at the Royal Agricultural University, Cirencester, Andrew’s main expertise and interest are in brain function in relation to behaviour.

Understanding the mechanisms in the brain that underpin behaviour helps us to understand the behaviour itself. Equally importantly, it helps us to understand how we can affect that behaviour, and how what we do may reinforce or reduce that behaviour. Andrew’s talk featured heavily on the neurotransmitter dopamine (a substance your body uses to send messages between nerve cells).

Dopamine is pivotal in learning, and in directing and motivating the animal towards positive resources and away from potentially harmful aversive (unpleasant) stimuli. Understanding the brain better enables us to develop better training techniques, and also to improve the husbandry of the horse.

ethogram live. The ridden horse ethogram consists of 24 behaviours, such as ears back, mouth opening, tongue out, going above the bit, head tossing, tilting the head, unwillingness to go, crookedness, hurrying, changing gait spontaneously, poor quality canter, resisting, stumbling and toe dragging. Sue and her team have shown that the presence of eight or more of the 24 behaviours warrants further investigation for pain or discomfort.

She pointed out the importance of recognising pain in horses, to enable earlier recognition of lameness, and to avoid punishment-based training.

Take home messages: Horses who are ‘misbehaving’ may be in pain.

The presence of several different ‘bad behaviours’ in the ridden horse could be an indicator that pain may be present.

Lack of recognition of pain behaviour in the ridden horse can lead to punishment based training.

Take home messages: When a horse learns, there are physical changes in the brain. This takes time and energy, and cannot happen as effectively if the horse is tired or stressed.

The physical changes in the brain need time to consolidate.

Understanding the brain better will allow us to train and care for our horses better.

Dr Sue Dyson: Why is the horse struggling in it’s performance – could it be helped?

A world-renowned expert in equine orthopaedics, with a particular interest in poor performance and subtle and complex lameness in sports horses, Sue has trained horses and competed at national level in both eventing and show jumping. She is an expert in diagnostic imaging, radiography, ultrasonography, scintigraphy and magnetic resonance imaging, and has published more than 250 papers in scientific journals.

Sue discussed the development of the ‘ridden horse ethogram’, a set of behaviours that indicate that a horse is in pain or discomfort. This ethogram has been developed through several scientific studies carried out at the Animal Health Trust, beginning with assessing photographs of horses and progressing to video assessment, and then using the

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Sunday 23rd February Mark Johnson: Hoof anatomy in action A qualified farrier with an interest in horsemanship, Mark focuses on finding the best and innovative ways to manage horses’ feet, ensuring they are comfortable and thus perform well for their owners. Mark is also a leading campaigner in the ‘Hope for Horses’ campaign, and is passionate about the welfare and well being of all horses.

Promoting shoeless where possible, Mark talked about health hoof anatomy, with some fascinating videos of the dissected hoof. He began by talking about the newborn foal, and the importance of a variety of surfaces for optimal development of the hoof structures.

Could we be risking the future health of our horses by keeping them on the ‘same’ surfaces, such as in a stable or a grass field? I think it’s possible. He went on to discuss internal hoof structure, and how the creation of space to allow blood and lymphatic fluid to circulate efficiently is essential for optimal hoof performance.

Again, his discussion was supported by video footage. Mark promoted the use of hoof boots where necessary, and also gave examples of his use of the Duplo composite shoe which he has found beneficial where 24/7 protection for the hoof is needed.

Take home messages: A healthy hoof has width at the heel.

The health of the hoof of the newborn foal could affect the future health of the horse.

If your horse is unable to work shoeless, consider hoof boots.

Dr Vibeke Elbrond: Understanding profound visceral myofascial connections Associate Professor in Anatomy and Biochemistry at the Department of Veterinary and Animal Science with a PhD in Anatomy and Physiology and a research field in biomechanics / functional anatomy with a focus on the functionality and integrity of fascia.

On the Sunday Vibeke showed us how the fascia that connects the muscles also connects to the internal organs. This, to be honest, is just mind blowing (as well as mind boggling). Her team have dissected out the deep ventral line, with connections to muscles as well as vital organs and structures of the body cavities.

This might give rise to a new approach and explanation for viscero-somatic pains and interactions, for example kidney and / or ovarian problems related to lumbar pain.

The ‘deep dorsal line’ includes muscles within the spine and also has an indirect contact to the meninges (dura mater), forming a connection known as the ‘myodural bridge’, which is believed to be involved in circulating cerebrospinal fluid.

Who knew that touching the outside of a horse could potentially have an effect at such a deep level?!

Take home messages: Everything in the body is connected to everything else.

What’s on the outside affects what’s on the inside.

The body is a miracle of engineering!

Dr Sue Dyson: What is new in lameness diagnosis?

A world-renowned expert in equine orthopaedics, with a particular interest in poor performance and subtle and complex lameness in sports horses, Sue has trained horses and competed at national level in both eventing and show jumping. She is an expert in diagnostic imaging, radiography, ultrasonography, scintigraphy and magnetic resonance imaging, and has published more than 250 papers in scientific journals.

Sue discussed several recent studies with us, in relation to lameness and poor performance. It’s so important to look for scientific evidence to support the tools used in diagnostics and treatment, and to continue to evaluate their effectiveness.

For example, a recent study suggested that a bone scan is unlikely to lead to a full and correct diagnosis of the cause(s) of lameness or poor performance in sports horses. Pattern recognition has been used to suggest that certain unexplained forelimb lamenesses might be related to cervical nerve root compression.

Pattern recognition has also been used in a study into horses with proximal suspensory desmopathy (PSD) who also had suspensory ligament injuries, which suggests that horses up to 5yrs old (including those who have not done any work) and overweight horses were more likely to have suspensory ligament injury alongside PSD. One study which shocked me showed that only 11% of people could correctly identify whether a horse was obese.

Take home messages: If your horse is struggling with poor performance, find a good vet!

No all techniques that are used to diagnose obvious lameness are as helpful in finding the root cause of poor performance.

Look for / ask for scientific evidence to support the techniques used in diagnositics and treatment of your horse.

Richard Hepburn: Tuning the equine engine to prevent poor performance Richard joined Willesley Equine Clinic in 2004, after completing a three year residency and Masters degree in equine internal medicine at the Marion DuPont Scott Equine Medical Center in Viginia, USA. He is a Diplomate of the American College of Veterinary Internal Medicine and a RCVS Recognised Specialist in Internal Medicine.

Richard talked about respiratory disease and gastric ulcers in particular.

An incredibly knowledgeable man and a good speaker, his presentation was heaped full of information. He pointed out that differences in athletic ability are mainly due to breed and individual variation, rather than to a better training regime, but there are some things you can do to help your horse perform better. These come into the categories of 1. Changing the things you can change, i.e. those that respond to training, and 2. Limiting limiting factors, i.e. reduce the effect of things that cause a problem.

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One of the limiting factors is respiratory function, since it doesn’t improve with training. Dynamic upper airway obstruction and inflammatory airway disease (equine asthma) are common in horses with poor performance, and Richard recommended preventative airway scoping for sports horses.

Equine Gastruc Ulcer Syndrome (EGUS) is not necessarily related to poor performance or behaviour, and it’s important to figure out which ones need treating. There’s a vicious circle involved where EGUS can cause stress and stress can cause EGUS (depending on the individual horse, stress might include transport, exercises, stabling, having another disease or illness, having more than two handlers). Some suggestions for reducing the likelihood of EGUS included: • Feed corn oil or rapeseed oil • Regular haynets (less than every six hours) • If hay is limited, feed 80% during the day, 20% overnight • Give hard feed before hay (this increases the saliva rate, which in turn helps to soften and break down the hay) • Feed a mix rather than pellets, to provide layering in the stomach • Feed chaff before exercises

Take home messages: Preventative airway scoping is advised for sports horses.

In man, colonic (hind gut) ulcers are largely asymptomatic (do not cause problems).

Gastric ulcer supplements are preventative, but not curative (they can help prevent the problem, but they cannot fix it).

Celeste Wilkins: How to ride a horse – unravelling the postural strategies of dressage riders Studying for a PhD in rider biomechanics and performance at Hartpury University, Celeste is using a Racewood Eventing Simulator and 3D motion capture to study rider biomechanics.

Her studies aim to use movement analysies to improve our understanding of riders technique, with implications for both training and rehabilitation of riders in the future.

Every rider has a strategy to absorb the movement of the horse that is influenced

by their anatomy and physiology, as well as skill, horse, goals, confidence, etc. Celeste is researching these strategies, focusing on identifying the components of rider strategies. She uses the Racewood Event Stimulator at Hartpury. Cameras track markers placed on the rider and allow her to compare riders using numbers, such as angles, displacement and velocity.

The results of her ongoing research will make for better coaching, more efficient rehabilitation, and off horse training that focuses on the individual riders needs.

Take home messages: Riders are looking for a combination of stiffness and softness that results in harmony.

Your unique way of accomplishing that is called your ‘rider strategy’.

Studies show that advanced riders seem to have more stable movement patters that rely less on visual cues and sit centrally in the saddle.

Panel discussion

Andrew reminded us that there are

At the end of each day there was a ‘panel discussion’. Audience members were invited throughout the day to write their questions down and put them in a box, which Gillian sorted through and presented to the presenters as a group on the stage. Some of the questions were aimed at just one presenter, but many benefited from collaborative answers, and so several of the presenters gave their thoughts. Bringing things to a close, Gillian asked each of them for their ‘top tip’. Sue talked about the importants of looking, feeling and seeing, and really thinking about what we look, see and feel in our horses. Seth recommended looking at the riders for asymmetry and considering how this might affect both horse and rider. Vibeke advised us to learn to look and see, and to think about what we see. Celeste pointed out that we are all individuals, and to embrace our individual patterns. She also talked about staying curious, and grabbing whatever opportunities come our way.

microanatomical (physical) changes that occur in learning which require both time and a relatively stress free environment, and so if we want our horses to learn then we must provide them with these things.

Conclusion At the end of day one I was on a high, regaling my sister with the many highlights of the day. By the end of day two, I was cooked, my brain completely fried. It’s a feeling I always get from a good learning opportunity, and I relish it. Next year the conference is at Belton Woods Hotel (NG32 2LN) on Saturday 21st February for a theoretical day then Arena UK (NG32 2EF) on Sunday 22nd February for a practical day. For more information visit www.horsesinsideout. com. See you there!

Physiotherapy for Spinal Cord Dysfunction Out-patient care • Gait re-education to reduce compensatory patterns of movement • Proprioceptive, balance and co-ordination exercise • Muscle strengthening and core stability training • Owner education and home exercises • Physiotherapy for Spinal • Cord Dysfunction

In-patient care • Pain management laser, pulsed electromagnetic energy, transcutaneous electrical nerve stimulation • Functional positioning sternal lying, sitting, assisted standing

Research Draper et al. (2012) found 3B laser reduced time to ambulation in dogs post laminectomy by 50%.

Gandini et al. (2003) found that 36/54 dogs with FCE that underwent physiotherapy, starting within 24-48hrs of onset, achieved spontaneous paw positioning in 2 weeks. This was supported by Kathmann et al. (2006).

• Maintain normal range of movement

Nakamoto et al.(2009) found that 21/26 dogs with fibrocartilaginous embolism improved with physiotherapy in 2 weeks but continued to improve up to 2 months after onset. They indicated that physiotherapy should be continued with follow up visits during this time.

• Normalise tone • Encourage voluntary movement • Hydrotherapy

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Pain Management And The Importance Of The Multidisciplinary Team In Rehabilitation For Our Veterinary Patients Dr. Katie Smithers BVSc certavp(va) pgcertvps mrcvs Veterinary Surgeon

INTRODUCTION

I

n human pain management it has been shown that an interdisciplinary approach is more likely to achieve an improved outcome, and significantly more cost effective.

So why, are our veterinary pain management patients so difficult to manage, and if the multidisciplinary team is so effective, why does this get overlooked in veterinary medicine; who should we be including and how?

Pain: Problems and Possibilities We have moved away from talking about chronic pain and to using the term maladaptive pain, which is recognised as a disease, with each individual patient suffering uniquely and to a different degree.

Pain can be challenging to recognise for any members of the team, and pain scoring is beneficial to quantify response to treatment. The author utilises the Canine Brief Pain Inventory or the Liverpool Osteoarthritis in Dogs (LOAD) metrology instrument for canine chronic pain patients, the Glasgow Composite Pain Scale for canine patients with acute pain and the Feline Grimace scale for feline patients.

Complications arise secondary to poor recognition of pain but also from concurrent disease, and many of our older patients suffer from co-morbidities such as renal disease or thyroid dysfunction, complicating all stage of management, from recognition through to resolution.

This is at least in part down to the multiple physiological processes involved in both nociception and pain perception.

Stimulation of peripheral nociceptors leads to the release of pro inflammatory mediators such as Nerve Growth Factor, Interleukin-6 and many others, causing peripheral vasodilation and oedema.

Peripheral transmission causes stimulation in the dorsal horn of the spinal chord and nociceptive transmission occurs through the anterolateral spinothalamic tract

to the brain. Here the thalamus axons project to the primary sensory cortex which locates the area of nociception and then the limbic forebrain creates an emotional response to the pain. Pain can then be influenced by descending inhibitory pathways and other cutaneous sensory inputs (gate- control theory).

This means there are a significant number of therapeutic targets for analgesic medications, a few of which are summarised below.

The class of analgesic mediation with the most veterinary evidence for efficacy is non-steroidal anti-inflammatory drugs. There is a good level of evidence to support the use of meloxicam, carprofen, and firocoxib (Sandersoln et al., 2009), all COX inhibitors preventing COX-enzymatic pathways and reducing the production of prostaglandins and therefore reducing the inflammatory cascade following peripheral stimulation.

However the non-steroidal anti inflammatory medications have recognised adverse effects, such as renal vasoconstriction, and both clinical and sub-clinical gastric ulceration have been reported. They also inhibit thromboxane and prostacyclin production which can cause coagulation abnormalities. There is now a more targeted type of nonsteroidal anti-inflammatory for our canine patients, which is an EP4 receptor antagonist which only inhibits PGE2 at one of its four receptor subgroups specifically responsible for PGE2 mediated pain, and so has a reduced side effect profile (Kirkby et al., 2016).

The mechanism of action of paracetamol is not well documented in our patients, and is thought to be via inhibitory descending serotonergic pathways, a metabolite which influences canabinoid receptors and some inhibition of prostaglandin synthesis (Jóźwiak-Bebenista et al., 2014).

Owing to its quick onset to action, this can be useful in patients with acute -on – chronic flares, those which do not tolerate NSAIDs, and in conjunction with other medication as part of the multi-modal analgesic plan.

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Opioids bind to receptors in both the peripheral and central nervous system, acting on transduction, plasticity and perception in the pain pathway. Opioids clearly play a part in managing severe acute pain, but our patients can develop opioid -induced hyperalgesia and decreased opioid responsiveness due to the central sensitisation, so they are not commonly used first line in our chronic pain patients. Also of note there have been studies showing tramadol is no better than a placebo at improving orthopaedic dysfunction or pain score in canine patients (Budsberg et al., 2018 and Malik et al., 2012).

As an NMDA receptor antagonist, amantadine reduces glutamate binding at NMDA receptors. Glutamate which is released with noxious peripheral stimuli causes activation of NMDA receptors, and is associated with hyperalgesia, neuropathic pain and reduction in opioid sensitivity. Amantadine should be considered for use in the initial multimodal approach in moderate to severe cases, or for patients who have worsening maladaptive pain, deterioration without inciting cause, or those who have become refractory to opioids. (Lascelles et al., 2008).

In addition studies have shown a low dose ketamine CRI lasting four hours can reduce oral analgesic requirements (Rychel, 2020). The author finds this can be useful as part of the analgesic plan in patients with an initially high pain score, those with allodynia or hyperalgesia, and patients where owner or patient compliance to oral medication is challenging.

Gabapentinoids reduce neuronal excitability through calcium channel blocking, they have also been shown to stimulate descending inhibition and influence the affective component of pain, with binding sites in both the peripheral and central nervous system (Chincholkar, 2018.). The author preferentially uses gabapentionids in hyperaesthetic patients, or those with nerve root signature on exam. They

can however cause sedation and should be incrementally dosed.

Species specific anti-NGF monoclonal antibodies Librela and Solensia have been recently licensed for use in pain associated with osteoarthritis in dogs and cats respectively. NGFs primary role in adults is pro-nociceptive, it binds to the TrkA receptors in peripheral nerve endings in subchondral bone, and leads to stimulation in the dorsal root ganglion and nociception as described earlier. Therefore by binding to the NGF the monoclonal antibody prevents signalling in the DRG, subsequently reducing nociception. They have few reported side effects, and as a monthly injection present a new treatment option for arthritic patients who are difficult to medicate orally, or have concurrent disease. (Corral et al., 2021).

Nuerokinin -1 receptor antagonists such as maropitant have been shown to be beneficial in management of visceral pain (Kraus, 2017), which may contribute to worsening orthopaedic pain, or increase overall pain scores if the patient is suffering from comorbidities.

The International Association for the Study of Pain (IASP) said in a statement on the 18th March 2021 that due to a lack of evidence from high quality research, it does not endorse the general use of cannabinoids to treat pain. IASP has also published a list of research priorities which need to be addressed in order to properly determine the potential efficacy, and to confirm the safety of, cannabinoids when used in the treatment of pain.

(Haroutounian, 2021). This applies to both human and animal patients and is in line with RCVS stance.

Acupuncture can be used in feline and canine patients, for many different conditions, and can be especially useful in patients with concurrent disease limiting pharmaceutical options, and as part of a multimodal analgesic plan. Analgesia is facilitated through release of endogenous opioids (Wen et al,. 2010), descending inhibition via serotonergic pathways (Lee and Warden, 2016) and electro acupuncture has be shows to reduce NMDA receptor activity in addition to this (Wang et al., 2006) .

So who can help - The Multidisciplinary Team A. Veterinary Surgeon i. Initial presentation The veterinary surgeon to whom the patient initially presents will diagnose

the condition or refer to an appropriate colleague. As far as possible the vet should implement a plan regarding conservative or surgical management and should discuss the expected outcomes and the team likely required for the patients successful treatment. ii. Surgeon Surgical intervention may be required for many different conditions and the surgical team should be involve in setting outcomes measures and post-operative care guidance for the other members of team. iii. Pain Management Referral to a pain management clinician may be indicated for patients with refractory pain and those requiring more intensive treatment. This may include but is not limited to: - Medication reviews/ prescribing (including inpatient treatment such as CRI) - Acupuncture and electroacupuncture

B. Physiotherapist Physiotherapy is a profession, not a selection of techniques, and ACPAT physio is always recommended due to the lack of title protection in the veterinary field. The physiotherapist’s role in our pain management and rehabilitation cases is diverse and pivotal, and owner engagement will have a significant effect on patient progress, outcome and prevention of future injury.

C. Weight Management It is well documented in human medicine that reduction in excess weight can reduce pain score.

Impellizeri et al, (2000) showed that a 11-18% weight loss in patients 11-12% overweight improved pain score, reduced oral analgesics and improved clinical outcomes.

For weight loss the patient should be fed 1x Resting Energy Requirement(RER), where RER = 70x (patients ideal body weight)^0.75 Although weight management planning is likely to be vet or nurse led, ongoing monitoring throughout treatment can allow identification of patients not meeting expected weight loss targets and inclusion of every member of the team will allow for early intervention.

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D. Nutrition and supplementation This can be nurse led, or vet led but there are important recommendations the whole team can reinforce to reduce the patient’s overall pain score and improve outcome and function. i. Deficiencies - Thiamine and B12 deficiencies are both associated with neuropathic pain and can cause permanent nerve damage (Daroff and Aminoff, 2014). Reduction in B12 can be seen with poor diet, increasing age and some medication eg proton pump inhibitors.

- Vitamin D deficiencies have been associated with inflammatory pain.

- Magnesium deficiency has been associated with both inflamatory and neuropathic pain and has also been used in treatment (Srebro, 2017).

- If patients have refractory pain or do not meet expected targets during rehabilitation, diagnostic tests may be indicated. ii. Supplementation The evidence base for dietary supplementation in veterinary patients is poor. The largest evidence base supports Omega-3 supplementation for increased activity associated with reduction in overall pain score (Rouche et al., 2010).

Olive oil can also be used as a natural anti-inflammatory but this needs to be accounted for within the weight management plan. iii. Recommendations - Adequate fluid intake – dehydration increases pain sensitivity. Discussing easy access to water at multiple heights locations and more locations available than the number of pets in the household - Appropriate dietary fibre intake – gut biome can affect pain score.

- Reduce refined carbohydrates – these can increase pain sensitivity. High blood sugar can also can contribute to neuropathic pain. It is important that outpatients are being fed commercially made or specially formulated diets specific to their species; human food (especially processed) should be avoided.

SUMMARY In conclusion our patients often present with a complicated clinical picture and a complex and intricate treatment plan is required. Pain management, effective rehabilitation and return to function are

inextricably linked and involvement of the multidisciplinary team and all clinicians at every stage, from diagnosis to discharge, is vital to maximise functional outcome for our patients. The author suggests a 12 week plan be agreed by all team members from the outset with set review periods, medication reviews and outcome measures, and a protocol for flagging any patients not meeting the set targets.

References Budsberg, S.C., Torres, B.T., Kleine, S.A., Sandberg, G.S. and Berjeski, A.K., 2018. Lack of effectiveness of tramadol hydrochloride for the treatment of pain and joint dysfunction in dogs with chronic osteoarthritis. Journal of the American Veterinary Medical Association, 252(4), pp.427-432.

Chincholkar, M., 2018. Analgesic mechanisms of gabapentinoids and effects in experimental pain models: a narrative review. British journal of anaesthesia, 120(6), pp.1315-1334.

Corral, M.J., Moyaert, H., Fernandes, T., Escalada, M., Tena, J.K.S., Walters, R.R. and Stegemann, M.R., 2021. A prospective, randomized, blinded, placebo-controlled multisite clinical study of bedinvetmab, a canine monoclonal antibody targeting nerve growth factor, in dogs with osteoarthritis. Veterinary Anaesthesia and Analgesia.

Daroff, R.B. and Aminoff, M.J., 2014. Encyclopedia of the neurological sciences. Academic press.

Haroutounian, S., Arendt-Nielsen, L., Belton, J., Blyth, F.M., Degenhardt, L., Di Forti, M., Eccleston, C., Finn, D.P., Finnerup, N.B., Fisher, E. and Fogarty,

A.E., 2021. International Association for the Study of Pain Presidential Task Force on Cannabis and Cannabinoid Analgesia: research agenda on the use of cannabinoids, cannabis, and cannabis-based medicines for pain management. Pain, 162, pp.S117-S124.

Nemke, B., Jacobson, P.B., Cozzi, E.M., Schaefer, S.L., Bleedorn, J.A., Holzman, G. and Muir, P., 2012. Effect of analgesic therapy on clinical outcome measures in a randomized controlled trial using clientowned dogs with hip osteoarthritis. BMC Veterinary Research, 8(1), pp.1-17.

Impellizeri, J.A., Tetrick, M.A. and Muir, P., 2000. Effect of weight reduction on clinical signs of lameness in dogs with hip osteoarthritis. Journal of the American Veterinary Medical Association, 216(7), pp.1089-1091.

Roush, J.K., Dodd, C.E., Fritsch, D.A., Allen, T.A., Jewell, D.E., Schoenherr, W.D., Richardson, D.C., Leventhal, P.S. and Hahn, K.A., 2010. Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs. Journal of the American Veterinary Medical Association, 236(1), pp.59-66.

Jóźwiak-Bebenista, M. and Nowak, J.Z., 2014. Paracetamol: mechanism of action, applications and safety concern. Acta poloniae pharmaceutica, 71(1), pp.11-23.

Kirkby Shaw, K., Rausch‐Derra, L.C. and Rhodes, L., 2016. Grapiprant: an EP 4 prostaglandin receptor antagonist and novel therapy for pain and inflammation. Veterinary medicine and science, 2(1), pp.3-9 Kraus, B.L.H., 2017. Spotlight on the perioperative use of maropitant citrate. Veterinary Medicine: Research and Reports, 8, p.41.

Lascelles, B.D.X., Gaynor, J.S., Smith, E.S., Roe, S.C., Marcellin‐Little, D.J., Davidson, G., Boland, E. and Carr, J., 2008.

Amantadine in a multimodal analgesic regimen for alleviation of refractory osteoarthritis pain in dogs. Journal of Veterinary Internal Medicine, 22(1), pp.5359.

Lee, E.J. and Warden, S., 2016. The effects of acupuncture on serotonin metabolism.

European Journal of Integrative Medicine, 8(4), pp.355-367.

Malek, S., Sample, S.J., Schwartz, Z.,

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Rychel, J., 2020, New Techniques in Chronic Pain Management. Live Webinar, Vet Show Academy, 13th January 2021.

Sandersoln, R.O., Beata, C., Flipo, R.M., Genevois, J.P., Macias, C., Tacke, S., Vezzoni, A. and Innes, J.F., 2009.

Systematic review of the management of canine osteoarthritis. Veterinary Record, 164(14), pp.418-424.

Srebro, D., Vuckovic, S., Milovanovic, A., Kosutic, J., Savic Vujovic, K. and Prostran, M., 2017. Magnesium in pain research: state of the art. Current medicinal chemistry, 24(4), pp.424-434.

Wang, L., Zhang, Y., Dai, J., Yang, J. and Gang, S., 2006. Electroacupuncture (EA) modulates the expression of NMDA receptors in primary sensory neurons in relation to hyperalgesia in rats. Brain research, 1120(1), pp.46-53 Wen, G., Yang, Y., Lu, Y. and Xia, Y., 2010. Acupuncture-induced activation of endogenous opioid system.

In Acupuncture Therapy for Neurological Diseases (pp. 104-119). Springer, Berlin, Heidelberg.

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The Hoof Horse Connection – ACPAT Conference 2021 Yogi Sharp DipWCF BSc (Hons)

T

o understand the hoof – horse connection there are certain principles of hoof biomechanics we must first appreciate. How the hoof functions and what affects its functionality, how the hoof morphs according to loads it experiences from conformational and pathological influences and finally how its shape then affects posture and predisposes to injury. These different factors create and perpetuate positive or negative morphology-pathology cycles.

Hoof capsule biomechanics were outlined by the studies of Thomason et al. (1998), the truncated oblique cone with thinner walls at the heels, affords the hoof certain normal deformations it uses to absorb concussion. The hoof is able to deform and return to shape, as long as it stays within its elastic capacity.

Due to the massive concussive forces the hoof experiences, it has another mechanism to disperse these shock vibrations. Three main haemodynamic mechanisms of the hoof were outlined

by Bowker, as well as the differences in strong versus weak systems. Differently conformed hooves will utilise different haemodynamic mechanisms with the ideal hoof perhaps utilising all three. This becomes important in the discussion of hoof morphology as the elastic capacity and therefore shape of the hoof is directly affected by its ability to disperse shock.

The hoof is a Hookean material, basically the amount of strain the hoof experiences, which is the amount of deformation in response to a stress, is directly proportional to the amount of stress applied. The size of the increments of strain depends on the stiffness of the object, its inherent composition. This composition also plays a direct role in the hoof’s elastic capacity. A weaker hoof will fail under the strains of a dysfunctional musculoskeletal system and inability to disperse shock, before a strong one does.

Douglas et al. (1996) outlined the elastic modulus of the different areas of the hoof, clearly showing that the heels had a lower elastic modulus to match their function of expansion, however this lower modulus means they will fail before the dorsal wall, changing the proportions of the hoof, creating negative cycles.

Hooke’s law and young’s modulus therefore become factors in dynamic morphological implications for the hoof.

Via its visco-elastic property, the hoof is

good at dispersing rapid shock when it is working efficiently, within that elastic limit. It deforms and returns to shape.

If we go outside that elastic limit, even slightly, we can get cumulative plastic deformations of that area, leading to measurable morphological changes over time. This is often insidious, leading to a lack of recognition until there are obvious hoof imbalances.

As well as morphological changes from dynamic forces, the hoof is also subject to time dependant forces. When we look at longer loading times, or even accumulative short loading times we start to see the effects of a phenomenon called creep. There is little research into creep in the hoof, but it applies to all viscoelastic materials.

Creep it is the tendency of a solid material to move or migrate slowly or deform permanently under the influence of persistent mechanical stresses. It can occur as a result of long-term exposure to high levels of stress even if they are below the yield strength, or elastic capacity of the material. The rate of deformation will be a function of the hoofs individual properties, exposure time, and the applied structural load.

This becomes important in the hoof connection discussion because if we have a centralised load, we can assume uniform strain within the hoof, and it will deform symmetrically. If we have off axis loading, then we will have increased load on one side and we can assume increased strain and deformation. This off axis loading can come of course from conformation or postural defaults in the horse as well as poor farriery. Through these phenomena the hoof becomes subject to the forces arising from the physiological state of the animal, the forces coming from above and the ground. The hoof is a deformable structure, subject to the weight of the horse and its interaction with the ground.

The morphology of the hoof is subject to the magnitude and direction of forces it experiences, and these create cycles.

Hoof shape is a factor of its mechanical function, its mechanical function will create morphology, affecting its mechanical function and so on. When these become inappropriate, negative pathological cycles are created. These cycles then extend beyond the hoof and spread through the whole body. Ideal physiology, creates ideal hoof loading, leading to ideal morphology, leading to

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ideal load on the musculoskeletal system.

Conversely, we can get negative influences from biological or environmental variations and a negative cycle ensues.

Another important factor in the link between the hoof and the horse, is the hoofs role as a neuro-sensory organ. The hoof is the primary way for the horse to gain information about the physical features of its surroundings. Its feedback comes from the distortion the hoof undergoes as well as the physical touch of the ground etc. This feedback instructs the horses posture and way of going and importantly its adopted postural stance.

The increased strain in the deep digital flexor tendon as a result of “long toe, low heel” conformations coupled with this change in proprioceptive input from the hoof are hypothesised to be responsible for changes in limb orientation. The ideal hoof gives ideal proprioceptive feedback, creates the ideal digit conformation, which enables correct limb orientation and this positive effect transfers through the entire musculoskeletal system.

The implications of poor hoof balance have shown to be different in the front and hind limbs. To understand the predispositions in the front limb we need to firstly outline some biomechanics.

Weller (2020) outlined that the extensor moment acting on the limb is calculated by the ground reaction force acting through the COP times the distance of the COP from the centres of rotation.

The extensor moment is a rotational and collapsing force acting on the limb.

In order for the limb to not collapse the counteracting force, being the tension in the flexor structures times their moment arms, has to increase. As the flexor moment arms are stationary, the only way to counteract the increased collapsing force is to increase strain in the flexor structures, predisposing them and the fulcrums they pass over, markedly the navicular, to injury. Waguespack and Hanson (2010, 2011, 2014) outlined the biomechanical considerations and stated that the primary source of pressure on the navicular bone (NB) is compression from the deep digital flexor tendon (DDFT) also stating that creating a straight HPA was an effective treatment for navicular.

Ruff et al (2016) expanded on this, expressing the increased compressive force on the NB from the DDFT in conformations exhibiting increased dorsiflexion. This was echoed by Uhl et al (2018) which stated conformations with

increased dorsiflexion were found to be mechanically predisposed to navicular and that DDFT lesions corresponded with areas of increased load. It is quite clearly outlined by the majority of the existing literature that “long toe, low heels” predispose to navicular syndrome.

The predispositions of this hoof conformation aren’t isolated to navicular syndrome. Clayton 1990 looked at the kinematic of the stride between a more upright foot and a more acute angled hoof where the hoof was allowed to grow into a broken phalangeal alignment. It found longer time to full solar surface bearing, and longer time to breakover, which has a biomechanical effect on the heels of the hoof and the navicular, but one very significant finding was that of toe first landings, something that has been linked to navicular, but also can cause other arthritic changes. As well as increased strain on structures such as the suspensory of the navicular and the whole podotrochlea apparatus, the concussive forces of toe first landings also predispose to articular ring bone, both high and low.

In the front feet most of the implications, although we will outline others later, of poor dorso-palmar balance are isolated within the digit. Mainly affecting the navicular region and distal joints. Mediolateral imbalances have been shown to affect the horse further into the musculoskeletal system along the front limb myofascial lines. At this point it is important to outline that outside of poor farriery, medio-lateral imbalances are a factor of poor conformation such as angular limb deformities or laterally offset hooves, as these create increased off axis loading leading to morphological deformations.

Kilmartin (2014) outlined an example of the implications along the front limb myofascial lines. He stated that even a small amount of imbalance can cause a change in muscle development and tension in the upper body, “In cases of medio-lateral imbalance in one of the forelimbs the medial wall of the hoof is more vertical, and the lateral wall is flaring out. Looking at the sole of the hoof the medial wall is higher than the lateral wall. In these cases, the Transverse, Ascending, and Descending Pectoral muscles are working along with the Subscapularis and Brachiocephalic to keep the fore limb under the body.

These horses again consistently show pain or reactivity over the cartilage of the scapula.” This statement clearly shows the compensations the horse has to make as a consequence of poor hoof balance.

As well as imbalance in the individual foot, imbalances between feet create

compensatory patterns within the horse. These imbalances between pairs of feet are great examples of full body compensations that arise and have been compared to subtle, sub-clinical lameness.

Hobbs et al (2018) found that the lower hoof in the pair had increased breaking forces as found in Wiggers et al (2015) and an increased vertical force, mirroring the pattern of Weishaupt (2008) for lameness.

Links between lameness, which has been shown to be linked with poor hoof balance, and compensations in the spine, were outlined by Landman et al (2004) and Gomez-Alvarez et al. (2007). With asymmetric propulsive forces the animal has to stiffen its spine and has an adapted hind limb locomotion in order to maintain straight line propulsion. Dr Ridgeway (2016) discussed her experience in some detail on the physiological effects on the musculoskeletal system and highlighted the benefits of interventions that increase symmetry and balance, expressing the “functional limb length disparity” of high-low hooves and described how the difference in joint angles affecting the muscular development. Ridgway (2016) also talked about vertebral function touched on by Hobbs et al (2018) who speculated that vertebral stiffening may be required to apply the locomotive adaptations required. Ridgway described the animal’s response to the imbalanced propulsive forces, “The horse has to twist his head and neck to keep the eyes level. Horses, therefore, often exhibit muscle pain, stiffness and spasm at the base of the neck. Moreover, because of dural torque (the tube in which the spinal cord is suspended and anchored), vertebral dysfunction and fixation occurs at the base of the neck.

This, then, accounts for the muscle tension and pain around the sixth and seventh cervical vertebrae. It also causes dural torque (twisting) at the level of the poll and at the lumbo-sacral connection.

Chiropractic issues are therefore common at all three levels as a result of the High Heel/Low Heel” Ridgway (2016) Dyson (2011) stated that poor hoof balance was directly linked to lameness.

Lameness creates full body compensations and therefore, hoof balance of the front feet can potentially create issues anywhere along the extensive myofascial system.

The implications of poor hind hoof balance have been shown to be different from the front limbs, suspected to be due to different ground reaction forces experienced as a result of a more propulsive job. Studies have also suggested the links to musculoskeletal issues being more profound in poor hind hoof balance as a result of the hind limb being connected to the trunk via a joint. When looking at

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the hoof horse connection in the hinds, posture becomes a very important factor.

Every horse will have biological variation, different length bones, different angles to their joints, but Something that is emerging as an ideal is the idea of vertical metatarsals at rest. DR Shoemaker, DR Gellman, and DR Rombach also express in their work and writings the ideal of vertical metacarpals and metatarsals.

When they are in this orientation, they are counteracting gravity efficiently and bearing load in pure compression. When they aren’t vertical like in a camped under posture, horses need to use immobiliser muscles as stabilising muscles and brace themselves before initiating locomotion and in general over stress the musculoskeletal system. Importantly having the ideal digit plays a vital role in creating this ideal of vertical metacarpals and tarsals. Poor hoof balance creates the necessity for compensatory adaptions and also distorts the neurological in put being received from the feet. This will directly affect limb orientation. In my research I have found this posture to be ubiquitous in the domestic horse population.

The causes are only just starting to be uncovered but come very much down to domestication. Influences such as confinement, eating from hay nets and modern riding techniques, and also hoof balance. Therefore, there is very much a fluid relationship of the hoof horse connection in the hind end.

While the implications for poor hoof balance in the front limbs are somewhat isolated for the main to the distal limb, in the hind pathology is referred to higher structures. Dyson et al. (2007) eluded to poor hind hoof balance being a predisposing factor in suspensory lesions, Mansmann et al. (2010) linked “long toe, low heel” conformation with gluteal pain, Pezzanite et al. (2019) concluded that horses with hind limb lameness localised to the distal tarsal and proximal metatarsal regions were likely to present with negative plantar angles and most recently Clements et al. (2019) correlated negative plantar angles with stifle pathology amongst others, with all of these studies highlighting the benefits of farriery intervention. Mannsman and Clements discussed the importance of the dorsal myofascial line and suggested further implications into the trunk of the horse. Pezzanite, Mannsman and Clements all discuss the camped under posture associated with poor hind hoof balance but focus on kinematic implications being responsible for the link to higher pathologies. Pezzanite alluded to the morphological implications on posture on the hind hoof, suggesting an increased load on the heels, anecdotally, experiential opinion would agree although there have been no studies to quantify this.

This is where the two-way fluid relationship becomes apparent. Either poor hoof balance creates an adapted posture, increasing strain on the dorsal myofascial line, predisposing to the associated pathologies. Or, the influences of domestication and possible higher pathologies create an adapted posture, increasing heel loading and creating a negative morphology. The cycle then becomes self-perpetuating whichever way it starts.

My personal research looked further into this cyclic relationship. I correlated the Presence of negative plantar angles with a camped under posture, measuring metatarsal angle. Then using thermography, I correlated this with the presence of increased surface emissivity suggesting areas of increased inflammation along the dorsal myofascial line. Then I did farriery intervention and measured the changes in posture. Farriery intervention to improve hoof pastern axis directly affected limb orientation.

There was no significant difference in hock angle pre and post intervention, despite a significant negative correlation between how broken back the hoof pastern axis was and metatarsal angle.

This also suggests, due to the reciprocal apparatus, that the stifle angle was not significantly changed. This pointed

toward the change in limb orientation coming from higher structures, likely the pelvis, or lumbo-sacral area. 91% of the cases had caudal thoracic inflammation, 91% had Sacro-iliac, 58% had gluteal, 58% had hamstring, 58% sciatic, 91% hock, 16% stifle and 25% had proximal metatarsal inflammation. The study strongly suggests a clear relationship between hoof balance, posture and musculoskeletal pathology.

This study shows the importance of a multi-profession approach to managing both hoof balance and higher pathologies.

Postural assessment should become part of farriery protocol and incorporated into intervention decisions. Veterinarians and practitioners should consider hoof balance could be a product of the physiological state of the horse as well as a contributing factor. Also acknowledging the importance of its correction in the treatment of the higher issues.

While research into the effects of medio-lateral imbalance in the hinds is limited, there is plenty of anecdotal and experiential evidence of its implications.

Medio-lateral imbalance in the hinds can create Rope walking/rope standing where the limbs are moved toward the midline, this creates uneven loading and wear of the hoof. This then exacerbates the necessity for the posture as the horse instinctively wants to stand on a level

surface. Conversely, improving the hoof balance commonly results in improvement of the static and dynamic posture.

Again, we see a cause-and-effect cyclic relationship. Irrespective of the causation, this relationship creates Imbalanced joint load all the way up the limb, notedly in the hock and problems in the stifle affecting collateral ligaments all the way up the limb.

This can create compensatory contraction of the abductor, a contracted iliopsoas and torque in the pelvis, creating issues with the Sciatic nerve, SI and lumbar.

This medio lateral imbalance behind creates issues along the dorsal and ventral myofascial lines. The fluid relationship is apparent, the poor hoof balance that may or may not be created by confirmation or pathology predisposes to pathology and postural adaptation. This brings us back to the recognition of the perpetuating cycles that occur between hoof morphology and higher pathology. As we further research the myofascial lines, and most relevantly the ones that extend into the hoof we will uncover further kinetic chain relationships between the hoof and the rest of the body. The more we look at the horse as a bio-tensegrity, the more we will appreciate that any anatomical point within its systems, can and will affect every other.

Physiotherapy for Hip Dysplasia Pain management • Heat, • Cryotherapy, • Transcutaneous electrical nerve stimulation • Laser

Hydrotherapy Neuromuscular electrical stimulation • to recruit weak muscles

Proprioceptive stimulation

Research

• e.g. Kinesio tape to facilitate muscle contraction

Laser has been found to increase cartilage regeneration and angiogenesis in rats and rabbits with arthritis (Cho et al. 2004, Shari. et al. 2008 & Lin et al.

2010); and better than NSAIDs at reducing pain in humans (Chow et al. 2009).

Gait re-education

Hydrotherapy has been found to improve strength and physical function in patients with osteoarthritis (Foley et al. 2003).

• To reduce compensatory patterns of movement

Rahmann et al. (2009) found early physical therapy & hydrotherapy increased functional strength after hip replacement.

Owner education & Exercise prescription

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The horse maintains an intact posture during dynamic exercise - no possibility of “cheating” strategies.

Available in X-Small, Small, Regular and Large.

£180.00+VAT

Exclusive ACPAT price £140+VAT Order online with discount code.

Laser Package

Vetkin-Tape

These packages are ideal for animal therapy practitioners as we can mix and match the probes and clusters to suit the required field of treatment.

A robust tape with good ventilation. 20% larger than human tapes and gives maximum results for animals.

Prices Start At

£6.25+VAT

Call or visit our website for latest pricing.

Large Wobble Cushions & Peanut Rollers Ideal for animal therapy.

Two limbs can be easily placed on the cushion, to improve balance and proprioception work.

Neurotrac Sports Muscle Stim

A dual channel muscle stim which has 15 preset programmes and the option to store 3 custom programmes.

Prices As Low As

£19.95+VAT

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10% off consumables and 5% off Equipment for ACPAT Members.

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www.trimbio.co.uk ACPAT - Equiband & Consumbales.indd 1

01403 597597 36

sales@trimbio.co.uk 03/06/2021 17:13

For current stock and full product details please visit our website.

Trimwave providing H-Wave Therapy The New Trimwave device delivers H-wave therapy, with fully selectable frequencies from 1Hz to 200Hz including the popular 2Hz and 60Hz frequencies.

It has a digital backlit screen that shows the battery charge state, selected frequency and intensity. The unit has an upgraded battery that is lighter and lasts longer, along with a simple push on\off button.

Included Accessories: Carry Bag Mains Charger 2 Sets of Electrode Leads 1 Packs of 5x5cm SelfAdhesive Electrodes 2 Mobile 3” Electrodes 2 5cm x 5cm Rubber Electrodes Operating Manual

£1,595.00+VAT Optional accessories and waist bag available.

Intelect Mobile 2 Ultrasound

Biomag 2 Base Unit & Accessories

The Intelect Mobile 2 Ultrasound offers dual frequency ultrasound - 1 and 3 MHz, with pulsed and continuous duty cycles (10%, 20%, 50% & 100%) available.

The Biomag 2 base unit has a range of frequencies offering a range of treatment options from soft tissue injuries, facture repair enhancement and pain relief.

Supplied with a 5cm² ultrasound applicator with additional optional heads available.

Optional bag and battery available for animal therapists that are on the go.

£495.00+VAT

Prices Start From

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www.trimbio.co.uk

Please visit our website for the full range of applicators we stock for the Biomag 2.

01403 597597 37

sales@trimbio.co.uk

Centaur Biomechanics International Equine Sports Science Virtual Summit, 3.10.2020 Sue Palmer, MCSP, IHRA, ACPAT and RAMP Chartered Physiotherapist, BHSAI

I

love learning, and I love writing, so on a wet and windy Saturday (thanks, Storm Alex), I was delighted to be attending the Centaur Biomechanics Internation Equine Sports Science Virtual Summint on 3rd October 2020. My 8yr old son Philip was even more pleased, because it meant he had a whole day on his tablet (yep, I managed to listen to the lectures over the shouts of ‘There’s a wolf coming’ and ‘You could rob that bank’ and ‘Oh no, I died again’ as he played online with a friend – thanks Roblox and Minecraft!).

The Summit, which was due to take place at Hartpury, was presented online by world class lecturers, and by the end of the day my brain was suitably fried. I have to say I found it helpful being able to soak up the information at home in my own surrounding, with coffee and chocolate biscuits (oops – sorry diet!) on tap, and able to write my notes on my iPad while I watched the Summit on my laptop and looked things up on my phone. Multi tasking at it’s best :-) There was so much to take in that I can only touch on each lecture here, but I hope to provide in depth articles on some of the subjects at a later date. One of the ‘benefits’ (?) of the online format was that there were only two 15 minute breaks through the day (as opposed to the usual half hour coffee break in the morning and afternoon, and hour long lunch break, to enable all female attendees time to get through the queue for the loo). So between 8.30am to 5.pm, there were 8 lectures from 8 experts – a lot of information to take in.

Dr Andrew Fiske Jackson – Surgical options for back pain: case selection to optimise outcomes

Summary In the treatment of back pain, make sure that any lameness has first been ruled out or addressed.

Focus on exercise based therapy, with the development of a core stability program.

This applies whether or not the horse goes for surgery.

Ensure that back pain exists, through measuring the movement of the back and assessing the horse’s response to pain relief (Bute, and nerve blocks of the back) Consider whether surgery may be the best long term option, as some studies suggest.

Associate Professor Thilo Pfau - The back as a functional link between the front and hind limbs: a (bio) mechanical perspective

Dr Anna Bystrom - The saddle pressure pattern - a little bit of everything

Summary

Measuring the pressures underneath a saddle is helpful, but also has it’s limits.

Knowing how to read the pressure pattern is essential. It’s not so much a saddle pressure ‘picture’ as a saddle pressure ‘movie’.

There are many different options avaialbe to measure saddle pressure, from different companies, and it’s important to research the options.

The saddle pressure picture can be useful in research, measuring saddle fit, and assessing back pain and lameness.

The saddle pressure picture is a combination of saddle fit and type, rider’s movement, and horse’s back and shoulder movement.

Lameness and back problems co-exist.

There is a ‘mechanism’ for unilateral (one sided) lameness. More movement = more force, less movement = less force, and a lame horse will put less force through the lame limb.

The ‘law of sides’ is a description of a compensatory mechanism with leads to a horse with a true left fore lameness perhaps appearing right hind lame, and a horse with a true left hind lameness perhaps appearing left fore lame.

I.e. a true forelimb lameness may make the horse seem lame on the opposite hind, and a true hindlimb lameness may make the horse seem lame on the forelimb on the same side.

The back is a link between the front and hind legs, and becomes more rigid when the horse is hindlimb lame. This is what causes the hindlimb lameness to create the illusion of a forelimb lameness on the same side as the lame hind leg (as opposed to the hindlimb lameness appearing to be on the opposite side when the horse is forelimb lame) Tools such as the Equigait are now available to make investigation of lameness more accurate.

Dr Sarah Hobbs - Equine locomotion on circles

Summary On a circle, the horse weight bears for longer through the inside limb than through the outside limb.

There is a more vertical orientation of the body (the horse is more upright) when the inside limb is on the ground.

The location of the centre of pressure under the hooves influences the stresses within the tissues.

The tissues on the inside of the hoof are stressed by effectively being ‘squashed’, whilst the tissues on the outside of the hoof are stressed by effectively being ‘stretched’.

Speed of the horse, radius of the circle, surface and banking (sloping on the outside of the circle) all influence turning mechanics, and the forces placed upon the horse.

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Summary

Dr Russell MacKechnie-Guire - The use and application of thermography to quantify saddle fit

Summary Thermography can be useful, but it’s sole use in the context of saddle fitting should be applied with caution.

The thermographic data in a recent study did not appear to be representative of increased saddle pressures (as measured by the Pliance system).

In this study, pressures under the saddle were more symmetrical (more even) when the horse was ridden in a correctly fitting saddle (as assessed by agreement of 5 qualified saddle fitters) compared to a wide fitting saddle or a narrow fitting saddle.

In all cases (correct fit, wide fit, narrow fit), there was more pressure under the front of the saddle than under the back of the saddle. This pressure was greater with the wide fitting and the narrow fitting saddle. This pressure was evident on the data from the Pliance pressure pad, but not on the thermographic data.

Dr Kevin Haussler - Physical examination and assessing back shape related to saddle fitting

Summary: ‘Back pain’ in the horse can mean many different things.

Assessment of back pain includes observing the horse in standing and

moving, as well as palpation (feeling) of the soft tissues and bony landmarks, and feeling the joint range of movement through the neck, back and rib cage.

Whilst shoe size (for humans) has been standardised for around 100 years now, there is as yet no standardisation of saddle size.

One of the difficulties in saddle fit is the difficulty of measuring the curves in the horses back. One of the many complications of this is that the horse changes shape over time.

A card system in standardising measurement of the horse’s back looks promising. This is commercially available from www.dennislane.com.au (Equine Back Profiling System).

Dr Nicole Rombach - Clinical dysfunction in the horse: a neuromotor control approach to therapeutic intervention

Summary Pain creates adapted movement.

When the pain is gone, the brain does not always correct the movement, and so it may

continue to be adaptive in the long term.

Whilst short term movement adaptation is beneficial (for example, limping when the horse has an abscess), long term movement adaptation is detrimental.

Core strength is essential in rehabilitation of movement.

“Use it or lose it” and “Use it and improve it” are helpful concepts to remember in rehabilitating movement following pain or injury.

Resolving pain and rehabilitation involves team work and clinical reasoning. First the pain must be resolved (or the movement will continue to be adaptive), then the movement can be retrained.

Dr Rachel Murray - Muscle development in rehabilitation: what can we use?

Some of the options for improving muscle development and retraining correct movement patterns include exercises in the stable (for example, carrot stretches), pole work (especially valuable in walk), training / rehabilitation aids (such as the Equiband), horse walker, treadmill (dry or water), and ridden work (including flat work and jumping).

A rehabilitation programme should always be individualised to the specific horse, as each horse responds in it’s own way.

Thank you so much to Intelligent Horsemanship for sponsoring me to attend this Summit. I’m off now for a well earned glass of wine…

Sue

Summary There are lots of reasons to focus on muscle development during rehabilitation following pain or injury. One of these is improved static (standing) and dynamic (moving) stability.

First of all, the pain must be taken away.

Physiotherapy for the Elderly Patient Pain management • • • • •

Heat Cryotherapy Transcutaneous electrical nerve stimulation Class 3B laser Soft tissue techniques to address compensatory muscular tensions • Muscle strengthening and core stability training

• • • • • •

Hydrotherapy Proprioceptive and balance exercises Controlled exercise programme Maintain and enhance joint leg range movement Gait re-education Owner education : - Manual handling advice - Encourage regular gentle exercise - Use of supportive bedding, coats, ramps, splints / slings / supports

Research Crook et al (2007) found that a home stretching regime for joint restriction increased the range by 7% to 23%.

Krstic et al (2010) found that TENS had the greatest effect on suppression of chronic pain in dogs with ankylosing spondylitis.

Laser has been found to be better than NSAIDs at reducing pain in humans (Chow et al 2009).

Kathmann et al (2006) found daily physiotherapy helped dogs with CDRM to remain ambulatory longer.

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Equine Gastric Ulcer Syndrome James Wallace BVMS GP CertEP CertEM (Int Med) MRCVS CertEP RCVS Advanced Practitioner Internal Medicine Equine Veterinary Surgeon

P

hysiotherapists are often the first point of contact for a client concerned with poor ridden behaviour and performance.

It is often necessary to rule out nonorthopaedic problems before embarking on treatment.

Equine gastric ulcer syndrome (EGUS), is one such common cause of poor performance, bad ridden behaviour, weight loss, and colic (Sykes & Jokisalo, 2014). As with all poor performance issues, teamwork, and liaison between different professions (physiotherapists, nutritionists, farriers, and veterinarians) is essential for a successful outcome.

EGUS is a broad group of inter-related conditions, which have different causal factors and management regimes. In this article we will summarise what EGUS is, and how you can identify it.

Figure 1: Evolution of the horse Horses have evolved over the last 50 million years from a mainly herbivorous omnivore, with a similar diet to modern pigs, to the modern horse on a forage based diet. The digestive system of the modern horse is configured to digest poor quality grass based diets, which are low in soluble carbohydrates (starch and fructan), and high in structural carbohydrate (cellulose and hemi-cellulose). Horses are well adapted to living in an arid climate with sparse grassland with high mineral contents such as the steppes middle Asia and themid-west of the USA; in conditions which would not allow other herbivores such as cattle and sheep to thrive (Mihlbachler et al., 2011).

Figure 2: Diagram of equine gastric anatomy The stomach is highly acidic (pH<1.4), and is split into 3 main portions (Sykes et al., 2015). The squamous portion (1) is an extension of the oesophageal lining and is a food storage vat. It has poor defence against acid exposure but has high stretch ability. If exposed to acid and bile from the gastric juices, it will oxidise and form squamous ulcers or EGSD (Figure 3). In a wild horse this is unlikely because the stomach would likely be full of fibre, which naturally floats on the gastric juice pool, and slowly makes its way down into the pylorus and further on into the digestive system. The glandular portion (2) is an acid secreting mucous membrane. This has good defences against acid, assuming there is no disruption to normal blood flow and hormone balances.Equine gastric glandular disease (EGGD) is not well understood, but can be erosions, ulcers, or thickened and inflamed membrane (Figure 4). The pylorus (3) has the same coating as the glandular portion, but is the barrier between the stomach and the small intestine. In addition, it acts as a pump and the trigger for normal intestinal propulsion of the food,measuring its sugar, fibre, and protein content; adjusting the digestive cycle using hormones and changes in the intestinal smooth muscle contraction. A more serious condition, delayed gastric emptying/gastric dilation can also be linked to ulceration, and is a cause of severe poor ridden behaviour (Bezdekova et al., 2020). There is no current link between the organism which can cause ulceration in humans (H. pylori) and horses.

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Figure 3: Squamous ulceration

Figure 4: Glandular and pyloric disease Initially, gastric ulcers were thought to predominately occur in highly stressed horses, or those under metabolic stress such as race horses and intensively stabled event horses. Recent work suggests the incidence in the general equine population of 45% increasing markedly with excessive exercise, cereal based diets, and stabling. In unpublished work by the author and other internists, there is a tentative link between obese horses with equine metabolic syndrome and EGGD. There is also emerging evidence of refractory EGGD and dietary allergens detected by serum IgE well testing (Wallace, 2021).

Horses with EGUS can show a wide variety of signs from weight loss, soft stools, teeth grinding, not finishing feed, colic, difficulty girthing, and poor ridden behaviour (Sykes & Jokisalo, 2014). Often they are uncomfortable on deep palpation of the left epigastric area, or application

of a tight surcingle. In addition some horse will have ventral abdominal spasm and pain in the L1-3lumbar area. Other tests such as faecal occult blood and saliva testing are of little or no diagnostic value (Wallace, 2017).

Investigation is relatively straightforward with gastroscopy now a routine outpatient procedure in most veterinary practices. It is well tolerated by horses, requiring only light sedation in most cases.

Treatment for EGUS differs from which areas of the stomach are affected, and the severity of disease. In all cases dietary modification is essential, with increased fibre intake being key. In addition adding in oil (rapeseed and fish oils), to each feed increases poly-unsaturated fatty acids, which can act as anti-inflammatory eicosanoid precursors in the stomach, and have a beneficial effect on blood flow.

Feeding a calcium-rich chaff (such as alfalfa) before riding acts as fibre trap for acid,and is especially useful in EGSD. Modifying exercise to reduce high intensity work, but increasing slow gait fitness is also beneficial (Luthersson et al., 2019; Sutton, 2014). Pasture turnout is not as protective as initially thought, and many horses can develop ulcers at grass if other predisposing factors are present (Sutton, 2014, Sykes et al., 2014, Wallace 2017).

Pharmacological management of EGUS relies on the use of ant-acid drugs (Sutton, 2014), proton pump inhibitors such as omeprazole / esomeprazole (which are particularly effective in EGSD), or the use of protectants such as sucralfate, which acts as a biofilm protecting areas of ulceration and encouraging healing (as used for EGGD). In some cases there additional medication may be required such as misoprostol (a synthetic prostaglandin) or prednisolone (a corticosteroid). In all cases, changes to diet and medication may need to be given over the working life of the horse (Lutherson et al., 2019).

Early identification of EGUS can lead to more successful treatment outcomes.

As such, as a medical professional, if you suspect gastric disease, liaising with the clients veterinarian to perform a gastroscopy will allow this condition to be ruled out as a cause of poor performance.

Bezdekova, B., Wohlsein, P., & Venner, M. (2020). Chronic severe pyloric lesions in horses: 47 cases. Equine Veterinary Journal. https://doi.org/10.1111/evj.13157 Luthersson, N., Bolger, C., Fores, P., Barfoot, C., Nelson, S., Parkin, T., & Harris, P. (2019). Effect of Changing Diet on Gastric Ulceration in Exercising Horses and Ponies After Cessation of Omeprazole Treatment. Journal of

Equine Veterinary Science. https://doi. org/10.1016/j.jevs.2019.05.007 Mihlbachler, M. C., Rivals, F., Solounias, N., & Semprebon, G. M. (2011). Dietary change and evolution of horses in North America. Science. https://doi.org/10.1126/ science.1196166 Sutton, D. (2014). Equine gastric ulceration syndrome: Treatment and prevention. In Veterinary Record. https:// doi.org/10.1136/vr.g4613 Sykes, B. W., & Jokisalo, J. M. (2014).

Rethinking equine gastric ulcer syndrome: Part 1 - Terminology, clinical signs and diagnosis. In Equine Veterinary Education. https://doi.org/10.1111/eve.12236 Sykes, B. W., Mcgowan, C. M., & Mills, P. C. (2015). Placement of an indwelling percutaneous gastrotomy (PEG) tube for the measurement of intra-gastric pH in two horses. Equine Veterinary Education. https://doi.org/10.1111/eve.12395 Wallace, JDG (2017). Equine Gastric Disease- a review. Proceedings of the Scottish Vet Fair – 2017.

Wallace JDG (2021). Weight loss in Horses. Proceedings ofVets4NHS Congress-2021

Physiotherapy for Cranial Cruciate Disease Pain management post op • Heat • Cryotherapy • Transcutaneous electrical nerve stimulation • Class 3B laser • Gentle weight bearing exercises to encourage healing and reduce swelling • Neuromuscular electrical stimulation to recruit hypotrophied muscles

Research

• Maintain range of movement

Berte et al (2012) found no instability was caused and lameness was improved 90 days post CCLR stabilised with lateral suture stabilisation (UWTM walking started at week 2).

• Gait re-education • Manual therapy to reduce compensatory muscle soreness

Full extension whilst weight bearing improves static quadriceps ef.ciency & helps reduce the risk of patella luxation (Lafaver et al 2007).

Risk of complication CCLR post op increased without physio (Lafaver et al 2007).

• Proprioceptive stimulation e.g. kinesiotape to facilitate muscle contraction

Monk et al (2006) found that 6/52 after TPLO, the physical rehabilitation group had signi.cantly larger thigh circumference and range of movement than the home exercise group.

• Hydrotherapy

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Research Digest Canine Articles Acevedo, B., Millis, D.L., Levine, D. and Guevara JL. (2019) ‘Effect of Therapeutic Ultrasound on Calcaneal Tendon Heating and Extensibility in Dogs’, Frontiers in Veterinary Science, 6(June). pp.185.

Kieves, N.R., Canapp, S.O., Lotsikas, P.J., Christopher, S.A., Leasure, C.S., Canapp, D. and Gavin, P.R. (2018) ‘Effects of low-intensity pulsed ultrasound on radiographic healing of tibial plateau leveling osteotomies in dogs: a prospective, randomized, double-blinded study’, Veterinary Surgery, 47(5), pp. 614622.

Renwick, S.M., Renwick, A.I., Brodbelt, D.C., Ferguson, J. and Abreu, H. (2018) ‘Influence of class IV laser therapy on the outcomes of tibial plateau leveling osteotomy in dogs’, Veterinary Surgery, 47(4), pp. 507-515.

Kennedy, K.C., Martinez, S.A., Martinez, S.E., Tucker, R.L. and Davies, N.M. (2018) ‘Effects of low-level laser therapy on bone healing and signs of

pain in dogs following tibial plateau leveling osteotomy’, American Journal of Veterinary Research, (8), pp. 893-904.

Rogatko, C.P., Baltzer, W.I. and Tennant, R. (2017) ‘Preoperative low level laser therapy in dogs undergoing tibial plateau levelling osteotomy: A blinded, prospective, randomized clinical trial’, Veterinary and Comparative Orthopaedics and Traumatology, 30(1) pp. 46-53.

McLean, H., Millis, D. and Levine, D. (2019) ‘Surface Electromyography of the Vastus Lateralis, Biceps Femoris, and Gluteus Medius in Dogs During Stance, Walking, Trotting, and Selected Therapeutic Exercises’, Frontiers in Veterinary Science, 6(July), pp. 211.

Ellis, R.G., Rankin, J.W. and Hutchinson, J.R. (2018) ‘Limb kinematics, kinetics and muscle dynamics during the sit-to-stand transition in greyhounds’, Frontiers in Bioengineering and Biotechnology, 6(November), Article 162.

Frye, C.W., Hansen, C.M., Gendron, K. and Von Pfeil, D.J.F. (2018) ‘Successful medical management and rehabilitation of exercise-induced dorsal scapular luxation in an ultramarathon endurance sled dog with magnetic resonance imaging diagnosis of grade II serratus ventralis strain’, The Canadian Veterinary Journal, 59(12), pp. 1329-1332.

Somppi, S., Tornqvist, H., Kujala, M.V., Hanninen, L., Krause, C.M. and Vainio, O. (2016) ‘Dogs Evaluate Threatening Facial Expressions by Their Biological Validity-Evidence from Gazing Patterns’, PLoS One. 11(1), pp. e0143047.

Cullen KL, Dickey JP, Brown SH, Nykamp SG, Bent LR, Thomason JJ, Moens NM. (2107) The magnitude of muscular activation of four canine forelimb muscles in dogs performing two agility-specific tasks. BMC Veterinary Research. 13(1), pp.

1-13.

Equine Articles Dyson, S., Bondi, A., Routh, J., & Pollard, D. (2021). An investigation into the relationship between equine behaviour when tacked-up and mounted and epaxial muscle hypertonicity or pain , girth region hypersensitivity , saddle- fi t , rider position and balance , and lameness. 1–10. https://doi.org/10.1111/eve.13440 Byström, A., Clayton, H. M., Hernlund, E., Roepstorff, L., Rhodin, M., Bragança, F. S., … Egenvall, A. (2020). Asymmetries of horses walking and trotting on treadmill with and without rider. (February), 1–10. https://doi.org/10.1111/evj.13252 Murray, R., Mackechnie-Guire, R., Fisher, M., & Fairfax, V. (2019). Could Pressure Distribution Under RaceExercise Saddles Affect Limb Kinematics and Lumbosacral Flexion in the Galloping Racehorse? Journal of Equine Veterinary Science, 81, 1–7. https://doi.org/10.1016/j. jevs.2019.102795 Byström, A., Clayton, H. M., Hernlund, E., Rhodin, M., & Egenvall, A. (n.d.). Equestrian and biomechanical perspectives on laterality in the horse Abstract. https:// doi.org/10.3920/CEP190022 Atalaia, T., Prazeres, J., Abrantes, J., & Clayton, H. M. (2021). Equine Rehabilitation : A Scoping Review of the Literature.

Bondi, A., Norton, S., Pearman, L., & Dyson, S. (2019). Evaluating the suitability of an English saddle for a horse and rider combination. Equine Veterinary Education, (August). https://doi. org/10.1111/eve.13158 Bye, T. L., & Lewis, V. (2021). Footedness and Postural Asymmetry in Amateur Dressage Riders, Riding in Medium Trot on a Dressage Simulator. Journal of Equine Veterinary Science, 102. https:// doi.org/10.1016/j.jevs.2021.103618 Christensen, J. W., Bathellier, S., Rhodin, M., Palme, R., & Uldahl, M. (2020).

Increased rider weight did not induce changes in behavior and physiological parameters in horses. Animals, 10(1). https://doi.org/10.3390/ani10010095 Gunst, S., Dittmann, M. T., Arpagaus, S., Roepstorff, C., Latif, S. N., Klaassen, B., … Weishaupt, M. A. (2019). Influence of Functional Rider and Horse Asymmetries on Saddle Force Distribution During Stance and in Sitting Trot. Journal of Equine Veterinary Science, 78, 20–28. https://doi.org/10.1016/j.jevs.2019.03.215 Uldahl, M., Christensen, J. W., & Clayton, H. M. (2021). Relationships between the Rider’s pelvic mobility and balance on a

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gymnastic ball with equestrian skills and effects on horse welfare. Animals. https:// doi.org/10.3390/ani11020453 Clark, L., Bradley, E. J., Nankervis, K., & Ling, J. (2021). Repeatability vs complexity: kinematic comparison between a dressage simulator and real horses. Comparative Exercise Physiology, 17(5), 467–474. https://doi.org/10.3920/cep200063 Squires, E. L., Squires, E. L., Hunter, R. P., Short, C. R., Myers, M. J., Farrell, D. E., … Squires, E. L. (2009). Journal of Equine Veterinary Science. 29(2), 2009.

Roost, L., Ellis, A. D., Morris, C., Bondi, A., Gandy, E. A., Harris, P., & Dyson, S. (2020). The effects of rider size and saddle fit for horse and rider on forces and pressure distribution under saddles: A pilot study. Equine Veterinary Education, 32(S10), 151–161. https://doi.org/10.1111/ eve.13102 Dyson, S., Ellis, A. D., MackechnieGuire, R., Douglas, J., Bondi, A., & Harris, P. (2019). The influence of rider:horse bodyweight ratio and rider-horse-saddle fit on equine gait and behaviour: A pilot study. Equine Veterinary Education, 1–13. https://doi.org/10.1111/eve.13085

The 11th Symposium of the International Association of Veterinary Rehabilitation and Physical Therapy Summer 2022 Cambridge, UK

The International Association of Veterinary Rehabilitation and Physical Therapy (IAVRPT) is an organisation that was founded over 10 years ago, bringing together scientists, educators, clinicians, and policy makers to stimulate and support the study of veterinary rehabilitation and physical therapy, and to translate that knowledge into improved animal rehabilitation worldwide.

In association with

We are delighted to announce that the 2022 IAVRPT Symposium is held in partnership with the Association of Chartered Physiotherapists in Animal Therapy (ACPAT) and hosted by the University of Cambridge.

We will be bringing you 3 days of world class lectures with small animal and equine streams running side by side. We have pre-symposium wetlabs, breakfast sessions and social events all held within the beautiful historic city of Cambridge.

Our symposium will focus on ‘Rehabilitation for All Creatures, Great and Small’ as we strive to strengthen the link between human and veterinary rehabilitation medicine.

Small Animal and Equine streams World class lectures from world class speakers Scientific programme Breakfast meetings Social events Gala event Professional Networking

We look forward to welcoming you to Cambridge in 2022.

www.iavrpt2022.org 43

Contact Us conference@acpat.org